Occasional fail to start when engine warm

[AndyH]

My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH

 

[Carl 1 Lucky Texan]

My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH

wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl

 

[AndyH]

wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl

Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

 

[Carl 1 Lucky Texan]

AndyH wrote:



wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl

Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

Nah, that temp sensor (engine - not thermo, though I'm not sure what
THAT one is) is to alter the ECU 'map' for cold weather starting/running
to replace what us oldtimers called a 'choke'. Usually, when it fails,
it continuously feeds the wrong value to the ECU such that the engine
stays in 'choke' mode. Gives rough running, sometimes stalling after
warm-up and very poor mileage. But I don't think it kills the spark on
start. There was an extensive thread at usmb about a similar issue, try
searching there. I just can't recall what was found. If the ECU isn't
happy, it won't fire the plugs. Something is either giving the ECU bad
info - or the coilpack is failing at high temp/intermittently. Have you
tried to retrieve a code with a reader? A GOOD reader known to work with
ISO OBDII ?

Carl

 

[Carl 1 Lucky Texan]

AndyH wrote:


My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional
input.

Carl

Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

Nah, that temp sensor (engine - not thermo, though I'm not sure what
THAT one is) is to alter the ECU 'map' for cold weather starting/running
to replace what us oldtimers called a 'choke'. Usually, when it fails,
it continuously feeds the wrong value to the ECU such that the engine
stays in 'choke' mode. Gives rough running, sometimes stalling after
warm-up and very poor mileage. But I don't think it kills the spark on
start. There was an extensive thread at usmb about a similar issue, try
searching there. I just can't recall what was found. If the ECU isn't
happy, it won't fire the plugs. Something is either giving the ECU bad
info - or the coilpack is failing at high temp/intermittently. Have you
tried to retrieve a code with a reader? A GOOD reader known to work with
ISO OBDII ?

Carl

I JUST remembered. The good news is, a MAF can be intermittent like this
- including the occasional stalling, the bad news is, its very expensive
to just throw one on if you're wrong. Um, has this vehicle had a K&N
or other brand 'oiled-style' air filter? They can sometimes cause
premature MAF failure.


I dunno

Carl

 

[Carl 1 Lucky Texan]

AndyH wrote:



wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl

Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

How many miles on the car? How many 3 years ago when the problem first
occured? Oh, and has the front O2 sensor been replaced? when?

Carl

 

[M.J.]

Something is either giving the ECU bad info - or the coilpack is failing
at high temp/intermittently.

Don't know about Suby's but these get fried fairly frequently
on GM products. Very similar if not exact same symptoms.

Is the car automatic?

GM had a notorious problem with something called an automatic
transmission torque converter solenoid. When the tranny warmed up
this 25$ electronic part would start failing, also intermittently. The car
would die shaking as the tranny torque converter would stay locked
and not disengage when coming to a stop. The distinguishing factor from
coilpack/coil module problem was the shaking. If the car shakes before
coming to a full stop and then dies it may be that your problem is some
solenoid that controls the converter in the transmission (?).

Does it die when idling only, that is, withuot warming up the
tranny? If so, then it is not the torque converter solenoid.

M.J.

 

[M.J.]

Don't know about Suby's but these get fried fairly frequently
on GM products. Very similar if not exact same symptoms.

Is the car automatic?

GM had a notorious problem with something called an automatic
transmission torque converter solenoid. When the tranny warmed up
this 25$ electronic part would start failing, also intermittently. The
car
would die shaking as the tranny torque converter would stay locked
and not disengage when coming to a stop. The distinguishing factor from
coilpack/coil module problem was the shaking. If the car shakes before
coming to a full stop and then dies it may be that your problem is some
solenoid that controls the converter in the transmission (?).

Does it die when idling only, that is, withuot warming up the
tranny? If so, then it is not the torque converter solenoid.

Forgot to mention, this problem would never show any
diagnostic codes (on GM cars), and was a pain in the butt of
so many GM owners. It also took aproximately 20 minutes
for the tranny to cool, and everything was back to normal
until the next episode.

M.J.

 

[AndyH]

On Sun, 03 Sep 2006 23:20:39 GMT, Carl 1 Lucky Texan


AndyH wrote:


My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional
input.

Carl



Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

Nah, that temp sensor (engine - not thermo, though I'm not sure what
THAT one is) is to alter the ECU 'map' for cold weather starting/running
to replace what us oldtimers called a 'choke'. Usually, when it fails,
it continuously feeds the wrong value to the ECU such that the engine
stays in 'choke' mode. Gives rough running, sometimes stalling after
warm-up and very poor mileage. But I don't think it kills the spark on
start. There was an extensive thread at usmb about a similar issue, try
searching there. I just can't recall what was found. If the ECU isn't
happy, it won't fire the plugs. Something is either giving the ECU bad
info - or the coilpack is failing at high temp/intermittently. Have you
tried to retrieve a code with a reader? A GOOD reader known to work with
ISO OBDII ?

Carl

I JUST remembered. The good news is, a MAF can be intermittent like this
- including the occasional stalling, the bad news is, its very expensive
to just throw one on if you're wrong. Um, has this vehicle had a K&N
or other brand 'oiled-style' air filter? They can sometimes cause
premature MAF failure.


I dunno

Carl

No oiled-style air filter
AndyH

 

[AndyH]

AndyH wrote:


My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl

Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

Nah, that temp sensor (engine - not thermo, though I'm not sure what
THAT one is) is to alter the ECU 'map' for cold weather starting/running
to replace what us oldtimers called a 'choke'. Usually, when it fails,
it continuously feeds the wrong value to the ECU such that the engine
stays in 'choke' mode. Gives rough running, sometimes stalling after
warm-up and very poor mileage. But I don't think it kills the spark on
start. There was an extensive thread at usmb about a similar issue, try
searching there. I just can't recall what was found. If the ECU isn't
happy, it won't fire the plugs. Something is either giving the ECU bad
info - or the coilpack is failing at high temp/intermittently. Have you
tried to retrieve a code with a reader? A GOOD reader known to work with
ISO OBDII ?

Carl

I had someone who knows about retrieving codes do it and he tells me
there was no codes present

I should check the coipack resistances next time this happens.

I think you're right. Something is telling the ECU bad info, so it
plays safe and does not fire.

AndyH

 

[AndyH]

AndyH wrote:


My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl

Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

How many miles on the car? How many 3 years ago when the problem first
occured? Oh, and has the front O2 sensor been replaced? when?

Carl

3 Yrs ago it would have been about 70,000 Miles
Today it is 88,000 Miles

Do not know re O2 sensor, I'll find out.

Andyh

 

[AndyH]

Don't know about Suby's but these get fried fairly frequently
on GM products. Very similar if not exact same symptoms.

Is the car automatic?

GM had a notorious problem with something called an automatic
transmission torque converter solenoid. When the tranny warmed up
this 25$ electronic part would start failing, also intermittently. The car
would die shaking as the tranny torque converter would stay locked
and not disengage when coming to a stop. The distinguishing factor from
coilpack/coil module problem was the shaking. If the car shakes before
coming to a full stop and then dies it may be that your problem is some
solenoid that controls the converter in the transmission (?).

Does it die when idling only, that is, withuot warming up the
tranny? If so, then it is not the torque converter solenoid.

M.J.

The car is automatic
There is a slight shaking when stalling from idle.
It has died after a long idle and without warming up tranny (ie parked
in driveway), so I guess that probobly eliminates the torque converter
solenoid.

Regards
AndyH

 

[Carl 1 Lucky Texan]

AndyH wrote:

On Sun, 03 Sep 2006 23:20:39 GMT, Carl 1 Lucky Texan



AndyH wrote:



My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl


Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew

How many miles on the car? How many 3 years ago when the problem first
occured? Oh, and has the front O2 sensor been replaced? when?

Carl

3 Yrs ago it would have been about 70,000 Miles
Today it is 88,000 Miles

Do not know re O2 sensor, I'll find out.

Andyh

That would be about the age a lambda sensor would start getting 'lazy'
though I suppose it COULD behave as you describe. It is also a fairly
inexpensive part that is not too difficult to change. I'd probably
change it if I were in you postion. Even if it doesn't cure the problem,
it's well over 2/3 its lifespan at least, and much cheaper than a MAF.

I suppose the IAC could use cleaning or something. It's a shame we can't
get a code.

Carl

 

[AndyH]

AndyH wrote:


On Sun, 03 Sep 2006 23:20:39 GMT, Carl 1 Lucky Texan



AndyH wrote:



My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl


Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew


How many miles on the car? How many 3 years ago when the problem first
occured? Oh, and has the front O2 sensor been replaced? when?

Carl

3 Yrs ago it would have been about 70,000 Miles
Today it is 88,000 Miles

Do not know re O2 sensor, I'll find out.

Andyh

That would be about the age a lambda sensor would start getting 'lazy'
though I suppose it COULD behave as you describe. It is also a fairly
inexpensive part that is not too difficult to change. I'd probably
change it if I were in you postion. Even if it doesn't cure the problem,
it's well over 2/3 its lifespan at least, and much cheaper than a MAF.

I suppose the IAC could use cleaning or something. It's a shame we can't
get a code.

Carl

Sound like the lambda sensor should be replaced and I will do that.
However as I'm not getting any spark at the plugs, during the can't
start period, I'm not hopefull that this will address my main problem.
I guess that goes for the IAC too.

Can you see any reason why a lazy lanbda sensor or a dirty IAC might
confuse the ECU into not triggering the igniter ?

AndyH

 

[Carl 1 Lucky Texan]

AndyH wrote:

On Mon, 04 Sep 2006 03:56:34 GMT, Carl 1 Lucky Texan



AndyH wrote:



On Sun, 03 Sep 2006 23:20:39 GMT, Carl 1 Lucky Texan




AndyH wrote:




My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl


Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew


How many miles on the car? How many 3 years ago when the problem first
occured? Oh, and has the front O2 sensor been replaced? when?

Carl



3 Yrs ago it would have been about 70,000 Miles
Today it is 88,000 Miles

Do not know re O2 sensor, I'll find out.

Andyh

That would be about the age a lambda sensor would start getting 'lazy'
though I suppose it COULD behave as you describe. It is also a fairly
inexpensive part that is not too difficult to change. I'd probably
change it if I were in you postion. Even if it doesn't cure the problem,
it's well over 2/3 its lifespan at least, and much cheaper than a MAF.

I suppose the IAC could use cleaning or something. It's a shame we can't
get a code.

Carl

Sound like the lambda sensor should be replaced and I will do that.
However as I'm not getting any spark at the plugs, during the can't
start period, I'm not hopefull that this will address my main problem.
I guess that goes for the IAC too.

Can you see any reason why a lazy lanbda sensor or a dirty IAC might
confuse the ECU into not triggering the igniter ?

AndyH

I can't. The system should really go into 'limp home' mode but.....

Again, the most common thing that both will not throw a code(in many
cases at least) but yield very poor running conditions is the Engine
Temp Sensor.

Maybe if you had a reader hooked up live and could monitor the OBDII
output during failure conditions?

Carl

 

[AndyH]

AndyH wrote:


On Mon, 04 Sep 2006 03:56:34 GMT, Carl 1 Lucky Texan



AndyH wrote:



On Sun, 03 Sep 2006 23:20:39 GMT, Carl 1 Lucky Texan




AndyH wrote:




My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl


Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew


How many miles on the car? How many 3 years ago when the problem first
occured? Oh, and has the front O2 sensor been replaced? when?

Carl



3 Yrs ago it would have been about 70,000 Miles
Today it is 88,000 Miles

Do not know re O2 sensor, I'll find out.

Andyh

That would be about the age a lambda sensor would start getting 'lazy'
though I suppose it COULD behave as you describe. It is also a fairly
inexpensive part that is not too difficult to change. I'd probably
change it if I were in you postion. Even if it doesn't cure the problem,
it's well over 2/3 its lifespan at least, and much cheaper than a MAF.

I suppose the IAC could use cleaning or something. It's a shame we can't
get a code.

Carl

Sound like the lambda sensor should be replaced and I will do that.
However as I'm not getting any spark at the plugs, during the can't
start period, I'm not hopefull that this will address my main problem.
I guess that goes for the IAC too.

Can you see any reason why a lazy lanbda sensor or a dirty IAC might
confuse the ECU into not triggering the igniter ?

AndyH

I can't. The system should really go into 'limp home' mode but.....

Again, the most common thing that both will not throw a code(in many
cases at least) but yield very poor running conditions is the Engine
Temp Sensor.

Maybe if you had a reader hooked up live and could monitor the OBDII
output during failure conditions?

Carl

Thanks for all your tips Carl, its really appreciated. I don't
suppose you know of some quick and dirty OBDII interface to a
notebook's RS232 port? I did hear of such a thing a while ago.

Regards,
Andrew

 

[Carl 1 Lucky Texan]

On Mon, 04 Sep 2006 16:18:08 GMT, Carl 1 Lucky Texan



AndyH wrote:



On Mon, 04 Sep 2006 03:56:34 GMT, Carl 1 Lucky Texan




AndyH wrote:




On Sun, 03 Sep 2006 23:20:39 GMT, Carl 1 Lucky Texan





AndyH wrote:





My 1996 Liberty / Legacy 2.2 L has a problem starting once the engine
has warmed. The problem was first noticed about 3 years ago. At that
time it only occurred about once every 2 to 3 months. As time passed
the rate of occurrence gradually increased. It is now likely to
happen more than once a week.

The symptoms of the problem are as follows:

" The car always starts from cold.

" There is no indication of a problem when driving (except for
occasional stall when idling).

" Occasionally the car fails to start once the engine is warm.
The engine cranks normally but there is no sign of firing.

" Once it has entered this failed state there is no spark at the
plugs.

" Once it is in this failed state it consistently fails to start
for up to 20 minutes.

" Once it has eventually successfully started, it may then be
stopped and started immediately and consistently until the next
episode which may be one hour or up to several days away.

" If there is a stall from idling, then it often enters the
failed state (where it will not start for up to 20 minutes)

" The ECU does not indicate any diagnostic codes after download.

" There is never any warning lights on the dash.


To date I have done the following:

Replaced both crankshaft and camshaft position sensors.
Replaced igniter with a Diamond unit.
Replaced HT leads.
Replaced main battery
Replaced ECU
Cleaned all visible earth points.
Coil primary and secondary resistance is always middle of acceptable
range when tested.
The main relay was opened today and its contacts look fine, and seems
to operate normally.

These actions have not had any effect on the problem.

Any help in solving this riddle would be very much appreciated.

AndyH


wow! - no code stored or CEL displayed?
You said no spark when failed, is there any indication of flooding at
all? The Engine (not coolant) Temp Sensor can fail and folks will may
not get a code.

Perhaps the next time it fails, you could spray some kind of coolant
(even water if you avoid the HT components) on various sensors that
haven't been replaced yet.

you might try posting this at www.ultimatesubaru.com . for additional input.

Carl


Thanks Carl for your feedback.

There is no sign of flooding at all. It just eventually decides to
start, maybe 5 minutes later or sometimes 20 minutes later. Once it
has started, then I can immediately stop and restart it always
successfully.

My wiring diagram shows what it calls an "Engine Coolant Temp Sensor"
and an "Evaporation Thermo-Switch". Are you referring to one of
these? I cannot see any other temperature related sensor. Where is
it located?

I suppose if the ECU has a routine that says [Do Not Start] if it
thinks the engine has overheated, then that could be the problem if
the temp sensor has got temporarily stuck out of range. Definitely
worth a look.

Regards,
Andrew


How many miles on the car? How many 3 years ago when the problem first
occured? Oh, and has the front O2 sensor been replaced? when?

Carl



3 Yrs ago it would have been about 70,000 Miles
Today it is 88,000 Miles

Do not know re O2 sensor, I'll find out.

Andyh

That would be about the age a lambda sensor would start getting 'lazy'
though I suppose it COULD behave as you describe. It is also a fairly
inexpensive part that is not too difficult to change. I'd probably
change it if I were in you postion. Even if it doesn't cure the problem,
it's well over 2/3 its lifespan at least, and much cheaper than a MAF.

I suppose the IAC could use cleaning or something. It's a shame we can't
get a code.

Carl


Sound like the lambda sensor should be replaced and I will do that.
However as I'm not getting any spark at the plugs, during the can't
start period, I'm not hopefull that this will address my main problem.
I guess that goes for the IAC too.

Can you see any reason why a lazy lanbda sensor or a dirty IAC might
confuse the ECU into not triggering the igniter ?

AndyH

I can't. The system should really go into 'limp home' mode but.....

Again, the most common thing that both will not throw a code(in many
cases at least) but yield very poor running conditions is the Engine
Temp Sensor.

Maybe if you had a reader hooked up live and could monitor the OBDII
output during failure conditions?

Carl

Thanks for all your tips Carl, its really appreciated. I don't
suppose you know of some quick and dirty OBDII interface to a
notebook's RS232 port? I did hear of such a thing a while ago.

Regards,
Andrew

please try searching the matter at www.ultimatesubaru.net . If you
post, mention being 'antipodean' and you may find some mates that hang
out there!

I think I recall a site with the schematic for an adaptoer, but then you
had to buy the software.

yeah, dig around here;
http://www.tari.co.za/cgi-bin/yabb2/YaBB.pl?board=dl1about

there are probably others. Check ebay as well.

Carl