92 Legacy SS ignition issue

[sliverumble]

Alright Ive got a 92 Legacy SS thats got some ignition issue. Started it up a few days ago after work, ran for a couple minutes to warm up then just died like I turned the ignition off. I tested the coilpack and ignitor, their all fine. Fuel pump is working and the filter isnt clogged. So at this point im thinking the ECU. Im getting the same voltage from both the ignitor and the coilpack, when I probe the middle wire on the coilpack the fuel pump turns on. Has anyone had issues like this? This is the second ECU Ive had in this car in the last 4 years and I find it odd that the ECU crapped out again. Please let me know if youve got an idea whats going on.

Thanks,
Grant

[wtdash]

Hi,
When my MAF died, the car would run and then die when coming to a stop and other random times.

GL,
Td

[sliverumble]

interesting, i hadnt thought of that. i do have an extra one, ill plug it in and see if that could be it. thanks

[sliverumble]

I swapped out the MAF and that wasnt the issue. I really hope its not the ECU but at this point im going to flash the codes and see what I come up with. Ive been trying to avoid doing that but at this point i dont have a choice I dont think

[Legacy777]

Can you elaborate what you mean by "when I probe the middle wire on the coilpack the fuel pump turns on."

Are you just using a multimeter to read voltage or are you using one of those test probes that is applying 12v to things?

[sliverumble]

im using a test probe

[Legacy777]

That middle wire comes from the ignition relay and also supplies power to the ignitor, fuel pump, and a few other sensors. So if you put 12v to it with the test probe, having the fuel pump turn on would be expected.

[sliverumble]

thats good to know, Im 99.99% sure the ecu went bad. Is there anyway fix that issue or is the ecu just weak on these cars. Ive traced, tested and checked all the ignition wires for poor voltage and continuity and they all seem to check out.

[Legacy777]

That's weird....because these ECU's aren't typically known for failures.

Are you not getting spark, is that the only issue? Are you getting fuel? If it's just spark, there may be an issue with a component in your car that is frying the ECU. Is the igniter & coil pack all stock?

I can see one ECU being a fluke, but two that would point to something else that is causing them to fail.

[sliverumble]

I thought its weird also that 2 ecus would fail. Yeah its just not getting spark. There is a signal/voltage going to the ecu but none coming from. The ignitor and coilpack are stock but I got a new coilpack plugged it in and nothing. I also got a working ignitor and nothing so thats what leads me to believe the ecu is bad

[sliverumble]

the only time im getting fuel is when I probe that midde pin on the coilpack with 12v. I know the fuel pump is good, far as I know the ecu isnt giving the signal for fuel pump to turn on. I saw some corrosion on the casing of the ecu in the car, it wasnt on the actual circuit board though. Who knows how many miles the ecu had on it when it was replaced about 2 years ago

[sliverumble]

my battery was decently corroded though as well as some of the connectors that sit right behind the battery, I cleaned those up to eliminate the slight chance that had anything to do with it

[Legacy777]

Does the CEL come on when you put the key in the ON position? If so, then the ECU should still be functional. If it's not on, I would double check to see if you're getting power to the ECU.

[sliverumble]

no the CEL doesnt come on when the key is in the ON position, I did double check that power is getting to the ecu.

[turbo970]

how does your crank and cam sensor check out? and what about your timing? if i remember right if ya belt slipped could cause no spark because the timing is off

[Legacy777]

If the CEL is not on with the key in the ON position and there is power to the ECU, then it's possible the ECU is dead.

Also have you checked all the fuses to ensure they're good.

Do you know what your voltage was reading at with the car running? I'm wonding if a bad voltage regulator in the alternator may be causing excessively high voltage and frying ECU's.

[sliverumble]

I did check the cam and crank sensors and they seem to be fine. Ill pull the timing cover off so see if by some random possibilty the timing belt popped off. The timing belt was changed at the correct interval. Im not sure what the voltage reading was when it was running so you could be right about a bad voltage regulator in the alternator. Ill have a working ecu on wednesday so Ill post what I find out. Thanks for all your suggestions

[sliverumble]

oh I forgot that i did check the fuses and they seem to be good and apparently I didnt not check the sensors fully, I checked the resistance on them

[sliverumble]

alright well I got it running, there was a loost/bad wire on the cam or crank sensor I forget which one it was. Now Im not sure if the ecu I got is for a turbo or non turbo because its not wanting to get on boost. Im going to check a few more things out to make sure that the ecu is the only possibility

[Legacy777]

What's the ECU part #?

If the engine is running, it's more than likely a turbo ECU, because the crank & cam sensor wiring is reversed on the non-turbo engines and the engine wouldn't run.

[sliverumble]

the part # is 22611aa694. That makes sense that the engine wouldnt run. It did run just not very well. How do you clear the codes off the ecu? My CEL is not coming on with my old ecu and there are several codes on there.

[Legacy777]

That is definitely a turbo legacy ECU.

You can clear the codes by following the info on my site.

http://www.surrealmirage.com/subaru/eng ... l#resetecu

[sliverumble]

Thanks for the info