I have a 1990 Legacy Wagon. After about 30 minutes of running it will just die. After it sits for apprx. 45 min. it will fire up and run for another 30 min. I have narrowed it to an ignition problem. Running through the tests in my Haynes manual, I connect a test light to the positive battery, and to the outer wires on the connector to the coil module. I'm not getting a signal while cranking the engine. It does check good though when the engine does run. I replaced the ignitor a while back, so I'm assuming it's good. The crank sensor is reading good resistance, so I guess it leads me to the ECM. Is there any way to check this? Where is it located on this vehicle. The manual says it is under the carpet on the passangers side floorboard, but it is not there.

 

Another problem encountered this morning that hasn't happened in the past, was the tach started dropping to zero while driving, then it would go back up to normal and the car would lurch for a second but it felt like the engine styed running...not sure though.

I have a 1990 Legacy Wagon. After about 30 minutes of running it will just die. After it sits for apprx. 45 min. it will fire up and run for another 30 min. I have narrowed it to an ignition problem. Running through the tests in my Haynes manual, I connect a test light to the positive battery, and to the outer wires on the connector to the coil module. I'm not getting a signal while cranking the engine. It does check good though when the engine does run. I replaced the ignitor a while back, so I'm assuming it's good. The crank sensor is reading good resistance, so I guess it leads me to the ECM. Is there any way to check this? Where is it located on this vehicle. The manual says it is under the carpet on the passangers side floorboard, but it is not there.

 

Another problem encountered this morning that hasn't happened in the past, was the tach started dropping to zero while driving, then it would go back up to normal and the car would lurch for a second but it felt like the engine styed running...not sure though.

 

That last realy points to a crank or cam angle sensor. That is how the tach reads engine speed. If it is not giving a signal, the ECU will not fire the plugs, as it needs that signal to determine timing. It sounds like you have a sensor going bad. Well, not going, actually. It is already bad, and it is getting worse. The ECM(ECU) is located behind the driver's kick-panel, under the dash. If you have an auto transmission, you will notice a square metal box right by the steering column. That is not it. What you are looking for is the metal box that is to the left of that one, and harder to get to. . .

 

Before we go further, do you get a Check Engine Light(CEL)?

If so have you read the codes to find out what the ECU is not liking? That will probably point you further along the path of finding out what is wrong than us just guessing. . .

I have a 1990 Legacy Wagon. After about 30 minutes of running it will just die. After it sits for apprx. 45 min. it will fire up and run for another 30 min. I have narrowed it to an ignition problem. Running through the tests in my Haynes manual, I connect a test light to the positive battery, and to the outer wires on the connector to the coil module. I'm not getting a signal while cranking the engine. It does check good though when the engine does run. I replaced the ignitor a while back, so I'm assuming it's good. The crank sensor is reading good resistance, so I guess it leads me to the ECM. Is there any way to check this? Where is it located on this vehicle. The manual says it is under the carpet on the passangers side floorboard, but it is not there.

 

Another problem encountered this morning that hasn't happened in the past, was the tach started dropping to zero while driving, then it would go back up to normal and the car would lurch for a second but it felt like the engine styed running...not sure though.

 

a bad ignitor can drive you to insanity. Il'd check the ignitor, or get one from a junkyard an swap it in (or three). This because of the timeline, sounds like once the mystery compnenet heats up, it develops an open and fails.

 

nipper

ECU is behind the dash

 

here's a pic

http://www.main.experiencetherave.com:8080/subaru/images/ecuhide.jpg

 

Instructions for checking the ECU are on my site (link in my sig)

I am getting a check engine light. I took it to a local mechanic, because I can't figure out how to get the codes to come up. He said the only code is a 35-purge solenoid. Which should not affect the ignition. Maybe a little instruction on checking that might put me in the right direction.

 

Legacy777- I'm not finding the link to test the ECU.

 

Hopefully I can pull up a code for a bad sensor if I can actually get them to read. Will they stay in memory, or do they actually have to be in the failed mode to throw a code?

 

Thanks everyone for the help so far

go to notes and tips,then engine related.

go to notes and tips,then engine related.

 

Got it. Thanks, that helps me with a couple issues than.

I got the codes out. I'm getting a 22 and 35. So should I go toward the Igniter again? Anyone know where I can pick one up for cheap?

I would check out the knock sensor (code 22). I'm not sure if that is the whole problem or not. It is located under the intake manifold on the drivers side of the car. It is a small black circle with 2 wires coming from it. It is probably cracked pretty badly. If it has a black connector, most people recommend to replace it with the new grey connector even a code isn't being thrown. I think it cost me 90-100, that is Canadian dollars though.

 

The fuel purge solenoid isn't a big big deal, but should be looked at sometime.

 

Start there, then go looking for other stuff if this doesn't fix it.

 

 

 

Beezer

Sounds to me that the knock sensor is sending out wonky (that is a technical term) signals that your ECU is gullible enough to believe. That causes the timing to be all over the plave, and the engine does not run reliably. . .

While I'm not sure the knock sensor would cause the car to shut off....it will cause you issues. I'd suggest clearing the codes, drive the car, and see what codes come back.

 

You'll still want to probably replace the knock sensor. As mentioned, they have a new revisions with a different color plug/connector. White is the new color, grey is the old color.

 

The canister purge solenoid can cause some issues, especially around idle speed if it's stuck open.

While I'm not sure the knock sensor would cause the car to shut off....it will cause you issues. I'd suggest clearing the codes, drive the car, and see what codes come back.

 

You'll still want to probably replace the knock sensor. As mentioned, they have a new revisions with a different color plug/connector. White is the new color, grey is the old color.

 

The canister purge solenoid can cause some issues, especially around idle speed if it's stuck open.

 

I replaced the knock sensor with the new white connector. The old one was cracked up pretty bad. I've got 100 miles, with one trip over an hour. I would consider it a SUCCESS! I replaced the purge solenoid tonight just to get rid of the code 35. Thanks for the advice.

 

Greg

Glad you got it taken care of.