Legacy wagon 92 Engine light and Rough idle...

[volny]

Bought this Legacy 92 about 6 months ago. First Subaru and I'm addicted to it!

Ran fine until my alternator fried, after mashing it up in pitch black coastal highway high beams on, radio, defogger etc... stupid of me.

Got that replaced, but right after that event my check engine light started coming up randomly. It's solid and comes with difficulty keeping idle, coughs and wants to stall. Once I turn the car off and back on, it goes away. I just don't want that to happen on the freeway.

I don't know much about cars, and try to learn how this one works, I was wondering if it could be an injector, 02 sensor, or just build up carbonation? I'm trying to run some techtron in it to clean it up right now, but actually my engine light showed up quicker today.

I tried to run a code test (u check I believe), but didn't showed any issue.

Any idea?

[lucas]

your codes will be stored in the computer so you can check em pretty easy, i dont have the link on how to do it but there littl connectors under your dash and you turn the key on then connect the two ends and the CEL (check engine light) will flash in a series which correlates to a trouble code. Just stick with it man these old cars are champs and need a little TLC. Welcome also

[07Evolved]

If I were you, l would reset the ECU first to clear the codes and see if it comes back. If it comes and goes, it could just be a faulty code that was stored.

[kimokalihi]

Here's the link to the procedure to retrieve DTC codes from the ECU. It's really easy and on the same page under the procedure is a list of the codes and what they mean.

http://legacycentral.org/library/literature/codes.htm

[volny]

THanks guys!

code check didnt show any code ...will run it again (and seems like there's few ways to do it). I tried a few times to reset obd1 "kenobi" as well, but will try one more time.

Yes these cars are simply AWESOME, rides like a champ. AWD + independent suspension paired with a aircraft engine, I feel like I'm riding a vintage spaceship lol....

Okay I'll update this week!

[volny]

BTW it has 230 000 miles on it....

[volny]

Update:

Ran a D-check (manual), no problem codes found steady light blinking.

Car runs good, maybe a slight loss of acceleration/power if anything.

Engine light comes on randomly , hard keeping idle, car wants to stall. Turn off / turn back on and it's okay again, engine light disappears...

When I start the car, I can see the speed needle acting unstable, car has a tendency to cough in 1st and 2nd gear if I release the accelerator to quickly.

What should I check? I really want to keep this car running, its too much fun to drive!

Can I perform a regular U-check on a manual ? I've only found the green connectors so far.

[Legacy777]

Yes, perform a u-check with only the black connectors to pull the stored codes.

[volny]

Thanks Josh!

Just did a U-check today, didnt show any trouble codes but my seatbelt light flashing lol, ran a D-check again, same nothing....

Few things that I noticed (but shouldnt affect the drivibilty?):

- AC belt has been taken off
- one bolt missing off the oil pan to the block (from underneath the car), about a 1mm gap between the two, very slight oil leak, but no drip.
- I can't find the EGR valve, I'm assuming its been taken off by the previous owner as well.

Also I had the alternator replaced two months ago, so the codes cleared at that time. I assume it should still show me if it detected anything wrong...

The investigation is still on!

[Jessekrs123]

- I can't find the EGR valve, I'm assuming its been taken off by the previous owner as well.

1st gens did not come with EGR, only a purge solenoid and a charcoal canister. EGRs were introduced in the 2nd gen 1995 models. (My father's 2nd gen 95 has EGR, my 1st gen 94 does not)

[volny]

Thanks Jessekrs123 that;s useful info right there!

I'm gonna try to check the idle air control valve and the idle air needle, sounds like the symptoms of build carbonation from what I've read so far...

[Legacy777]

Try checking the U-check right after you see the CEL come on. Not in all instances will a code be stored. I've run into this before.

As for the seatbelt blinking, that's a different test.

http://main.experiencetherave.com/subar ... tdiag1.jpg
http://main.experiencetherave.com/subar ... tdiag2.jpg
http://main.experiencetherave.com/subar ... tdiag3.jpg

[volny]

Dude you rock ! thanks !

[volny]

Performed an oil change a week ago (better late than never...), oil looked like thick caramelised molasse, no wonder is was getting hot at times...drained all that crap out, put a new filter et voila! Engine light does not come on anymore!

I also finally found the right black plug to perform a diagnosis (I was was plugging the wrong set) and got all the trouble codes I needed. Will post for advice on different tread!

Thanks for all of you kindness and coolness in making fixing a car a "fun" project!

[volny]

Updates 2 years later...

Idle problem came back a few months ago.

I did my research and ended up cleaning the iac valve pouring a load of seafoam in it. A lot of smoke came out and the idle settled down (did that twice).

Now my ide is set at 500/600rpm when sitting at the traffic light. It's usually stable, but once a week it will start idling like crazy going from very low to getting stuck at 1500+ rpm and slowly coming down.

Sometimes it comes down so low that it stalls. It stalls mostly at traffic light but it has stalled while driving before.

The idle goes down really low and when I gas it up it feels like something is clogged until I pass 2500 rpm then the idle needle moves free. So between 100rpm to 2000rpm roughly the idle needle does not want to come up.

The car starts right back every time.

Any idea?

[kimokalihi]

What were the codes you found? That could be a lot of things. Bad fuel pump, timing off, clogged fuel filter or injectors, tps, coolant temp sensor, etc.

[volny]

I have had no codes so far.

Timing belt just been replaced. Timing done, and idle re-adjusted.

Fuel filter just replaced.

I seafoamed the injectors a few times last year by pouring it into the pcv valve.

It almost feels to me that it is fuel related (gut instinct), the car lacks a little bit of power compared to before, and it has a slight fuel smell at times.

[volny]

Oh and HAPPY NEW YEAR everyone!!!

[volny]

Also when I cleaned the iac it blew a cloud of smoke so big you couldn't see a thing in the parking lot...

[kimokalihi]

Pouring seafoam into your pcv valve will clean the intake and runners and the inside of the combustion chambers but not your injectors. That would need to be done through your fuel tank. But I'm skeptical of its effectiveness this way for anything other than mild routine maintanence.

[Legacy777]

Just an FYI, the RPM you are reading is not 500 rpm, it's 750 rpm. The large ticks are 500 rpm incriments, while the smaller ticks are 250 rpm incriments. The small tick between 0 and 1 just make it look like it's 500 rpm, but it's actually 750 rpm.

You can see what I mean in this picture

http://www.main.experiencetherave.com/s ... G_5845.JPG

As for the idle problem, how many miles are on your car?

[lucas]

My car has 205,000. I know its old and im almost positive my problem is wiring.

[lucas]

totally hijacked this haha sorry disregard

[volny]

no worries Lucas

My car has 255000 miles on it

[volny]

I finally decided to bring my car to the shop to get it diagnosed.

They said it may be the alternator that's going bad and would cause the rough idle a low rpm (other that that car is running fine).

Any take on that?

I have already had problem with the alternator and replaced it before, so I may have a small electrical glitch...

Any advice on which alternator brand to buy? I'd like something solid if it is a weak spot on my car.

My car has 205,000. I know its old and im almost positive my problem is wiring.