Misfires and other stuff

[TurboLaserRS]

I hate to start another thread about what's going on now in light of all the other threads but here's the deal. My laser is running ungodly rich. I can tell by the plugs that it keeps fouling out. If you try to rev it, it will rev fine from 900 to 2.8k and then its like it hits a rev limiter. It spits and sputters. I have no check engine light, and I just replaced the plugs. The turbo is spooling just fine, I have the lines that ran to the bcs blocked off so I should just be on wastegate pressure. What should I be checking? The only things I have seen resolve this kind of condition were a ECU problem. I do have one very peculiar symptom. There is a grey plug on the back of the intake manifold toward the throttle body side, and if you plug it in with the key turned to run it makes this buzzing electrical sound I can't really describe. If you plug it in the car hardly runs at all. I have used the search and I don't know wtf to do. If anyone has some insight please let me know. I can take a video of the buzzing if needed. Thanks.
_Edit: The buzzing sound comes from inside the throttlebody area. Anybody know what the heck this is?

 

[Talon IV]

I would double check the plug wires and coils just to be on the safe side. Next double check all your vacuum lines and make sure they are where they need to be and in good repair. Also for safe measure, pop the timing cover off and just make sure the timing belt is in good shape and it has not jumped teeth. After doing that, then maybe see about ECU issues. But as far as that buzzing sound goes, I may have to see a picture of what exactly you are talking about... almost sounds like you are playing with the Idle Stop Switch?

 

[GSLENK]

Might be the idles speed controller motor going bad. it is a rapidly activating solenoid to help control idle.

Sounds like you have a leak of the right size might be why it idles so good without the ISC. then when you plug in the ISC it doesnt know what to do, and the idle goes to crap.

Id do a BLT next, its pretty cheap.

 

[TurboLaserRS]

Okay so here's my update for the day. I had a tard moment while trying to change the fuel filter and all kut rounded off the edges of the lower fitting. Because of where I was standing the direction to loosen it was opposite of what I was thinking.
Now my car is no longer fouling plugs so badly after the fuel filter change but still won't seem to rev over 3k except every once in awhile.

 

[TurboLaserRS]

Is it possible that it is stuttering at 3k because the base timing isn't set yet?

 

[GSLENK]

3k under load or sitting in neutral?

 

[TurboLaserRS]

Both in neutral and while driving. I found out that electical noise is my ISC motor by the way, I'm pretty sure its bad.
Edit: yeah my ISC is toasted. Its supposed to be between 28 and 33 ohms and it fluctuates from 50 to 800! I still don't see this being the source of the stuttering though.

I wanted to add that I overlooked the fact that my flex pipe is destroyed. The outside mesh is about 1/3rd missing. I would venture to say I'm losing about half my exhaust from the flex pipe before the cat. Could this be a problem? I figured since it was OBD1 it wouldn't matter.
At this point I'm willing to try anything. I'm going to cut the flex section off and weld a new one up.

 

[smokestack]

Could be the cat converter, I heard some people having problems or not being able to rev high or go over a certain speed never had i happen to me though so just my 2 cents.

 

[TurboLaserRS]

Dude you are absolutely right. I cut the flex pipe off and started it up and it revs fine now!!

-Misfire is back again. Too good to be true I guess. Fml.

 

[TurboLaserRS]

View My Video

Don't know if you can tell its misfiring or not.

 

[TurboLaserRS]

I have an update for anybody also experiencing this problem. I finally figured out how to get my ecu out and I found out that one of those black capacitors leaked out onto the board.

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I'm pretty sure the board is ruined, its kind of distorted looking, for the lack of a better word. Its definitely got rust or corrosion in a little area behind it. If you ever have a misfire that won't go away, check your ecu!! I will update this thread again once I get a new ecu.

 

[TurboLaserRS]

Its fixed! This thread is resolved. A guy from my local forum stepped up and GAVE me a rebuilt 90' ecu for free! I plugged it in and started it up. The misfire was there for maybe 2 seconds and then it stopped and hasn't been back. I FINALLY got to drive my car for the first time :thumbup: and I will tell you.. I am a DSMER for life. If you ever have a misfire that won't go away, pull your ECU and look at the caps.

 

[buhay6]

Thats awesome man! good to hear your rolling again, the kindness of some dsm'ers is astounding!

 

[TurboLaserRS]

Well that didn't last long. I got my car legal today and decided to go for a drive. It starts hard like its running on 2 cylinders. It was running fine yesterday, the only thing that changed was the oil and the coolant. I gave it some gas and it seemed to be misfiring then it smoothed out. I go for a drive and its completely fine all the way to the gas station. On the way back I notice when letting off the gas my tachometer goes up instead of down. Then getting back on it it stutters and then boost kicks in and it takes off like nothing happened. UGH.. did my ecu crap on me again? I'm getting frustrated. Should I bother replacing the spark plugs? The wires don't seem to be arcing I checked it in the dark. Oh and my oil pressure gauge is at the lowest mark at idle but yet there's no dummy light on.

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[TurboLaserRS]

Hooked up a mechanical gauge today. My car is running 22psi oil pressure @700 RPM. So my gauge is bad I guess.

So here goes the development for the day. I took my plug wires off and pushed the ends out further. Then I plugged them all back up. Runs fine! Problem solved right? Well I thought so. I drove all around town no problems anywhere. Then when I'm turning onto the road I live on its like I dropped 1 or 2 cylinders. I could maintain speed but I couldn't accelerate. I see that the check engine light is on, then all the sudden the light turns off and it accelerates like normally. WTF? So its doing it in my driveway, I take off and replug all the wires again, starts up and runs fine. 10 sec later it does it again. Does this sound like a coil pack problem or is my ignition module crapping out on me?

 

[supertalon91]

Did you ever fix ## problem? I also have a laser rs 92'. My engine melted #1 piston while racing a vette on the interstate at 124 mph. I rebuilt the engine and start it for the first time, but it runs for a min or less perfectly fine, then it starts misfiring and I gotta stay on the throttle to keep it alive long enough to find out and try to diagnose it. Sucks because im on break in period. dont want to kill my fresh engine. So it sounds like im in the same boat as yourself.

 

[TurboLaserRS]

Mine ended up being a wire problem. I never could see wires arcing, but I took my accel wires off and put the stockers back on. Haven't had any trouble since. I've noticed that the little sleeve on the ends of the wires likes to work down too far, and sometimes that seems to cause a connection issue with the coil but everthing still appears connected.