Hard idle and loss of intermittent power

[SubaruLegacy 270k]

Hello,

 

I love my 1990 Legacy. It has 283k+ miles on it. I got in a small finder bender a few weeks ago and I've been working on fixing it up. Before the accident the car was running great. I've replace the hood, drivers headlight and the radiator. In accident the radiator overflow bottle was pushed into the timing belt cover. This both cracked the timing belt cover and wore a hole in the overflow bottel. I have replaced both the overflow bottel and the timing belt cover.

 

After doing all this the car was still not running right. So I replaced the timing belt, the camshaft sprocket(the face original one had been bent from the accident) and the camshaft position sensor. I also got a code saying that there was a problem with the oxygen sensor. I have replace the oxygen sensor and the PCV.

 

Currently the car will start. On a cold start it revs to about 2,000 and then it will drop down in die. On the next turn of the key it will start up rev high again, then drop down almost die, pickup again, then almost die. It will do this for awhile before evening out. If I try to drive the car without letting it fully warm up it has no power.

 

Once the car is warm it runs ok. It idles a little hard and sometimes has no power. On the freeway at a constant speed sometimes it will have a stutter and then go back to normal.

 

Oh yeah I've also cleaned the AICV and swapped it out with another one thinking that maybe that was the problem. I'm still getting an O2 sensor code after replacing the O2 sensor.

 

Thanks for your help.

[SubaruLegacy 270k]

Just to add one other thing...I did a reset of the ECU and things seem to be running better. I drove around town for awhile without having the check engine light come on. Once I got one the freeway though the light came on. I have not pulled the code yet but I'm guessing it's going to tell me it's the oxygen sensor.

[SubaruLegacy 270k]

So I pulled the code and it was the O2. I did another reset of the ECU and it has not come back yet but I haven't driven the car on the freeway over 60 yet. Still having the cold start issues...

[SubaruLegacy 270k]

So the check engine light came back on today when I was on the freeway going 70 but it did not come on before that and I drove about 20 miles before it came on. Once I got off the freeway and driving for a little the light went off. I'm guessing it's the oxygen sensor again. I did replace the oxygen sensor with a universal one. Do you think that might be the problem or is the problem else where? This is the second universal oxygen sensor I've tried.

 

Thanks!

[SubaruLegacy 270k]

I'm still working on this thing. Haven't figured out what the problem is. I removed the coolant temperature sensor and tested it and found that it was providing readings to the ECU that indicated that the car was hotter than it really was on the cold end. This seemed to help a little with the warming up of the car. Here are the current symptoms:

1) Hard to warm up. On a cool day the car will take about 5 minutes to warmup before it is drivable. If you try to drive it before it's warm it will have no power. Also on first start it almost always dies. The car will rev to about 2k then quickly drop down, try to idle and die.

 

2) On the freeway cruising the car will sometimes jurk. If you release the accelerator or accelerate a little the jurking will stop.

 

Thanks so much for you help!!!

[Baddog]

I should say post this in the 2nd gen forums it will get more attention.

 

But check the MAF (clean it with Mass air flow cleaner)

Idle Air control valve could use a good cleaning again (even though you replaced it)

 

I would also compression test the engine to see the condition it's in. You could have a vacuum leak somewhere. Really anything.

[SubaruLegacy 270k]

Thanks Baddog. I cleaned the MAF last weekend and didn't notice any difference. I also clean the IACV before I put it on. The one that I took off didn't look very dirty at all though and I'm not even sure it was bad. I'll try and do a compression test this weekend and see what I get.

 

Thanks again for the suggestions and I'll post over on the second gen side and see if any one has some ideas.

[SubaruLegacy 270k]

Fixed!!!! I think. I found a small hole in one of the spark plug wires. That fixed the problem I was having with the car jerking on the freeway at 2750 RPMs.

 

Then after lost of testing and trying a few different parts I figured out that the MAS was going bad. After replacing it with another used one my cold start issues went away and I have not had an 02 sensor code for the past 3 days.