1990 RS Legacy throwing codes?

[sperla123]

My beast sometimes throws a wobbley. I notice it mostly during winter, when its cold or when its nearly empty on the gas. It only does it when it I go to start it up, and when it does start with the check engine light on, it has an irregular idle and light flashes in no pattern at all. Turn it off, start it again and it is gone (back to normal) or drive off and its disappears. I've spent about NZ$730 overall at three different places on trying to get it sorted, but with no luck. No-one seems to know what it is? I know about the plugs and reading the codes, I've had it hooked up to the computer and sure it has a couple of codes in there, but those parts of the engine have been checked and have no faults. Dunno???

I have pieces of paper that have the codes from two different diagnostics services from the computer at the workshop, but are at home. I will post them soon.

Thanks for any help or theories on the problem

Az


http://img.photobucket.com/albums/v259/ ... RSpic3.jpg

(I HATE ALL CAPS TOPICS - DLC)

[Legacy777]

what codes were in the computer immediately after the CEL was on? Did you make sure to clear the codes once you read them, so if there was anything that popped up again, you'd know it was a new code.

[sperla123]

These scans were done on it and the codes were cleared straight after. Then the next scan showed this and then were cleared. Those things have been checked, everything is A1 and even replaced a couple of them and its still doin it? Faulty sensors maybe

http://img.photobucket.com/albums/v259/ ... -08-03.jpg

http://img.photobucket.com/albums/v259/ ... -11-03.jpg

Thanks for any help or theories on the problem




And another thing......
Each time i have had a computer check them or a manual check (me pushing plugs together & reading flashes), i have cleared them afterwards, but what is the proper way of doing that? I have told of many ways, what do you suggest?

I have been trying this lately-

How to reset the ECU
To erase trouble codes from the computer you have two ways. The first I have not verified, but I'm sure it works.
ECU clear memory procedure is as follows for auto and manual transmissions:
1. With engine at operating temperature, turn engine off. Place gear shift lever into park (auto transmission cars only).
· Locate the two ECU check connectors, for most cars they are located under the steering column and consist of a black plastic male and female connector, and a green male female connector. The exact location of the connectors varies with the different year models, but generally they are located under the steering column on the drivers side.
NOTE: sometimes they are still taped over with some small amount of plastic tape, so look hard, they will be there!
With the ignition OFF connect black to black and green to green.
· Turn on ignition, do not start the engine, (and for auto transmission, cycle the gearshift lever from park to neutral and back to park ), depress the accelerator pedal to full throttle and hold for a few seconds, and then release. Start engine and then drive for at least one minute, keeping road speed above 10 mph.
· ECU is now re-set.
· At this point the check engine light should start to flash the all clear signal (steady 1/2 second interval flashes). If the check engine light does not flash, or indicates some other sequence, there is a fault present in the system, and should be checked for necessary repairs.
· Once done, stop the car and turn off the engine.
· Disconnect the plugs.

OR

just negative terminal off for a few hours on battery

Does anyone know if this works? Any suggestions?

Thanks

[sperla123]

A better explain a little better, this is pretty much what it is doin...
The check engine light doesn't stay on, it flashes irregularly as the car idles rough, But give it a rev or take off and by the time you stop again, the idle is back to normal and the light goes away. It does it generally when I go to start it, problay 3-4 times a week when its cold weather like now. Its like a sensor is playing up? Had it checked and no one seems to know. Its no big deal, its not wrecking or stuffing my car, its just a pain the ass.

[Legacy777]

Connecting the two plugs together is what I have used, and it does work to clear the codes. You can verify afterwards to make sure the codes are cleared.

The battery method does work sometimes, however I have had people try it and it not work.

When the problem occurs, and the CEL flashes irregularly. Have you recently checked the codes right after it happens? It sounds like this is happening on a pretty regular basis correct?

The scans you posted are from almost a year ago.

[Bubba-Ugly]

My CEL comes on after the engine warms up and I let the engine idle, for example, at the first stop light about two miles from my house. When the engine is cold, the light remains off as long as I keep the engine RPMs high.

I pulled the codes, and found about five or six faults; the cam sensor, the crank sensor, air flow sensor, the IAC valve, the neutral safety switch.

I tried clearing the codes by disconnecting the battery, but that did not work even after several tries.

Could this be a bad MPFI box?