distributor all the way advanced on '87 GL

[elijahs]

trying to sort out a little problem on an '87 GL Wagon I'm using for
the summer (it was my dad's backup car). It's got 215k miles on it
(!) but aside from occasional lifter noise, it runs alright. I did a
complete tune up and oil change, and that helped, but it's still a
little bogged down in the lower RPMs.

When I checked the distributor, it's been advanced all the way to the
end of the adjustment zone (and backing it off makes the engine run
worse). This seems odd to me, but I don't know what would cause the
distributor to be misadjusted in such a way that full advance is still
short of correct.

What should I look at next? I know it's an old car, but I'd like to
get everything as close to running right as possible...

thanks for any help!
elijah

 

[Hachiroku $B%O%A%m%/(B]

trying to sort out a little problem on an '87 GL Wagon I'm using for the
summer (it was my dad's backup car). It's got 215k miles on it (!) but
aside from occasional lifter noise, it runs alright. I did a complete
tune up and oil change, and that helped, but it's still a little bogged
down in the lower RPMs.

When I checked the distributor, it's been advanced all the way to the end
of the adjustment zone (and backing it off makes the engine run worse).
This seems odd to me, but I don't know what would cause the distributor to
be misadjusted in such a way that full advance is still short of correct.

What should I look at next? I know it's an old car, but I'd like to get
everything as close to running right as possible...

thanks for any help!
elijah

I am by no means a Suby expert, having just bought my first one (an '89
GL), but I had something similar happen to an 88 Supra after changing
plugs/wires.

Try disconnecting the fuse to the ECU. This will force the ECU to
'relearn' the engine parameters and may reset the advance.

It worked on an '88 Supra and an '89 Mazda...it may work for you.

 

[johninKY]

Can't adjust/check the distributor timing without first connecting that
green test connector located by the wiper motor.

 

[elijahs]

Can't adjust/check the distributor timing without first connecting that
green test connector located by the wiper motor.

Well, I'm doing the rough-cut no-timing-light version of a timing
adjustment. I'm traveling for the summer and my timing light is far
far away.

So, I'm advancing the distributor until it starts to misfire. Except
it's not - the engine runs faster and faster until I hit the limits of
the adjustment track. That seems weird - shouldn't the correct spot
be somewhere you *can* go too far past? it doesn't seem to be on this
one right now. It was set to the upper limit when I got to the car.

So my question is - what would cause this distributor to have a
"correct" timing point that's off the adjustment area? What can I do
to try to "pull" the timing back a bit?

thanks!


e

 

[johninKY]

It is completely normal for the engine rpm at idle to increase when the
timing is advanced. Any engine can tolerate too much ignition timing at
low rpm/no engine load conditions. Problem with this is when the rpms
increase and the engine is under a load, too much timing will eventually
melt a hole in one or more pistons.

Really need to find that green test connector. This test connector is only
used to set the ignition timing and should be unplugged all other times.
If it is currently connected this means the timing is "locked". In other
words the ECU cannot advance/retard the timing.

You can get the timing within a few degees + or - without using a timing
light. Just turn the distributor housing one way or another until the
hold down bolt is centered in the adjustment slot.

What happens when you fully turn the distributor in the other direction?
Engine should stall or at the least, just barely run.

Don't pull the distributor thinking it may be a tooth off. It can be a
real bear to reinstall.

Another possibility is the timing belt that powers the distributor could
be a tooth or two off. Did anyone recently replace the timing belts?

 

[elijahs]

Really need to find that green test connector. This test connector is only
used to set the ignition timing and should be unplugged all other times.
If it is currently connected this means the timing is "locked". In other
words the ECU cannot advance/retard the timing.

You can get the timing within a few degees + or - without using a timing
light. Just turn the distributor housing one way or another until the
hold down bolt is centered in the adjustment slot.

ah, now we're talking. Ok, I'm not taking into account how the ECU is
adjusting the situation as I rotate the distributor. So the best
approach is - attach the green connector and center the distributor,
and wait 'til I can get my hands on a light to do the fine tweaking...

Just what is the ECU doing? when I first got to it I centered the
dist (without connecting the green connector) and the car was very
bogged down under 3000 rpm, so I switched it back. Without connecting
the green connector, what does the ECU do to adjust to make the car
run better so fully advanced?

What happens when you fully turn the distributor in the other direction?
Engine should stall or at the least, just barely run.

yes, the engine rpms drop as I retard the timing.

Don't pull the distributor thinking it may be a tooth off. It can be a
real bear to reinstall.

thanks, I won't...

Another possibility is the timing belt that powers the distributor could
be a tooth or two off. Did anyone recently replace the timing belts?

not that I know of but this is an oooold car that came from a little
old woman (literally) and my dad has only put 500 miles on or so.


thanks for the feedback, this is interesting! I'll play with it
today.


elijah

 

[johninKY]

Don't know exactly how the ECU regulates the timing but since this
distributor has no vacuum can, however it is done it isn't mechanically.
Do know the ECU sends a signal to the coil that allows it to fire. My
guess is there is some sort of time delay function hardwired inside the
ECU.

Since you don't have a timing light, there is no need to connect the green
test connector. Just center the distributor and maybe just a tad on the
advance side and you'll be in the ballpark.

When you do have your hands on the timing light, do connect the test
connector. Timing marks are on the flywheel or flexplate.

Since you are aware of the green test connector, plug it togather and turn
the ignition key to the RUN position. The ECU is located behind that panel
under the steering coluum. It has a little green window that will flash
trouble codes if any are stored.

Trouble codes can be determined by counting the flashes. All long flashes
equal ten and the faster flashes are one. Example: 4 long flashes
followed by 3 short flashes is trouble code 43.

Good chance you may have one or more stored. Find any just post and I'll
check a list that tells what they are.

Another possibility here is a small vacuum leak somewhere. Engines don't
like them at low rpms. Also has the fuel filter been recently replaced?

 

[elijahs]

Since you don't have a timing light, there is no need to connect the green
test connector. Just center the distributor and maybe just a tad on the
advance side and you'll be in the ballpark.

ok - this was my first move, way back when. The car drove like the
engine was mired in molasses up until about 3000 rpm. so I moved the
advance up to almost-all-the-way - still muddy... so I moved it to
fully advanced (where it was originally) and it runs alright now.

When you do have your hands on the timing light, do connect the test
connector. Timing marks are on the flywheel or flexplate.

I think finding a borrowable timing light is my next move.

Since you are aware of the green test connector, plug it togather and turn
the ignition key to the RUN position. The ECU is located behind that panel
under the steering coluum. It has a little green window that will flash
trouble codes if any are stored.

just to make sure - the green test connector is in the engine
compartment , right in front of the driver. Two green connectors that
fit together. Right near it, there are two smaller white connectors
that aren't connected. any idea what those are or if they're
important?

When I connect them and turn the car to the ON position, some sorta
motor or something starts cycling in the engine compartment - it
sounds like my cell phone on vibrate. I tore off the under-steering-
column panel and found the SPFI controller. With the test connector
connected - the red LED blinks 5 times, rapidly, over and over... this
code wasn't in my Chilton's. Any idea?

speaking of Chiltons -- the Set Timing section refers to setting the
"Idle Switch" to "on" (as well as connecting the green connector) but
doesn't give details. What's that about?

Another possibility here is a small vacuum leak somewhere. Engines don't
like them at low rpms. Also has the fuel filter been recently replaced?

hmm, that's a good idea, I'll get under there with some starting fluid
and check that too.


thanks for the help, it's really nice to be able to talk to people
that know what's going on in there...

elijah

 

[elijahs]

oh - and one other thing - the "Check Engine" light *never* comes on -
not before starting the car, even...

 

[johninKY]

The 5 flashes means there are no stored trouble codes.

The location of the green test connector is correct.

I think, fairly sure, the unplugged white connector is used for a more
indepth trouble code retrevial. I never used it in any of my old GLs.

Leave both unconnected.

You have a problem but I don't think whatever it is has anything to do
with the distributor timing.

 

[Rick Courtright]

just to make sure - the green test connector is in the engine
compartment , right in front of the driver. Two green connectors that
fit together. Right near it, there are two smaller white connectors
that aren't connected. any idea what those are or if they're
important?

Hi,

It's been a while since mine blew up, so this is off the top of my head:
IIRC the white connectors are used to effect something like a "warm
boot" and erase at least some of the codes the ECU has stored. Seems the
check engine light flashed when I connected mine, too. If you have no
CEL under any circumstances, the bulb could be dead. The whole dash has
to come out to replace a bulb if it's like mine, so might as well get a
whole bunch of bulbs and replace 'em all while you're in there. Seems
Subaru used a proprietary bulb back then, too, so you'll probably end up
at the dealer.

Best to double check everything I've said here, though. As I said, off
the top of my head...

Rick