Hard starting 94 Legacy

[smokey]

I borrowed a family members 94 Legacy to fix a repeatedly dying
battery. Easy fix; the 'parking lights always on' button was toggled
on. However, after charging the battery the 'check engine light' came
on and car was hard to start. It cranks fine but won't start on the
first minute/2-3 tries; then starts, runs rough for a minute or 2--with
the fan running, then runs fine.

My initial guess was a temp sensor but I just can't reconcile the
coincidence of the battery being charged just before the CEL came on.
No trouble codes yet. Car has about 110k miles and has been
meticulessly maintained. Any help greatly appreciated.

 

[Carl 1 Lucky Texan]

I borrowed a family members 94 Legacy to fix a repeatedly dying
battery. Easy fix; the 'parking lights always on' button was toggled
on. However, after charging the battery the 'check engine light' came
on and car was hard to start. It cranks fine but won't start on the
first minute/2-3 tries; then starts, runs rough for a minute or 2--with
the fan running, then runs fine.

My initial guess was a temp sensor but I just can't reconcile the
coincidence of the battery being charged just before the CEL came on.
No trouble codes yet. Car has about 110k miles and has been
meticulessly maintained. Any help greatly appreciated.

Well, having the 12V removed for a while should cause the ECU to go back
to 'factory map' for starting and operation, until a few drive cycles
allow it to 'learn' and utilize the sensor readings.
I also would expect there to be a code stored if the CEL came on. I
think there is a 'blink number' you can retrieve by connecting some
green (?) connectors under the dash. That should point to a likely path.
At 110K you could have 2-3 sensors getting 'lazy' or bad. If it is
original, I'd suspect the front O2 sensor as well as, as you say,
possibly the Engine Temp Sensor.

good luck

Carl

 

[mulder]

Well, having the 12V removed for a while should cause the ECU to go back
to 'factory map' for starting and operation, until a few drive cycles
allow it to 'learn' and utilize the sensor readings.
I also would expect there to be a code stored if the CEL came on. I
think there is a 'blink number' you can retrieve by connecting some
green (?) connectors under the dash. That should point to a likely path.
At 110K you could have 2-3 sensors getting 'lazy' or bad. If it is
original, I'd suspect the front O2 sensor as well as, as you say,
possibly the Engine Temp Sensor.

good luck

Carl

Yes if the CEL is on there should be a code stored that will point you
in the right direction. You can find instructions on how to read the
code here-
http://www.troublecodes.net/Subaru/

 

[AS]

Some 94 and 95 year model vehicles had problems with the crankshaft
sensor, causing the problem you describe. I will try that one first
unless you can get the code read.

 

[Carl 1 Lucky Texan]

Some 94 and 95 year model vehicles had problems with the crankshaft
sensor, causing the problem you describe. I will try that one first
unless you can get the code read.

excellent suggestion!

Carl

 

[smokey]

Thanks all. Guess I'll join the modern world and read the codes. Maybe
d/c the battery and see if it resets. Appreciate all the commmets.