Little Help? Sc Is Bogging Out And Dying At Idle, Tried Everything!?

jjm983

Registered User
Ok, I am still having the problem with my SC bogging out and dying after starting it. It usually does it on cold starts, It will run good for about 2 secconds and then it will start bouncing up and down from 1,000-200 RPMs untill it just dies. it will go good once you drive it around for awhile, it also always has a put put sound from the exaust and the idle is always up and down. there is just something not right. I replaced the MAF and bolth the 02's because those were the only ones throwing codes. I also Cleaned my IAC with sensor cleaner. so im thinking either I have to buy new IAC valve or maybe someone has a different idea??!! Please help
 
The bouncing sounds like the EEC-IV trying to manage idle but something is throwing it out of the range of adjustment it can handle. When I've had that issue, it's been a problem with ignition. Either poor quality spark, or way overly rich fuel.

Do you have a methanol injection system? Switch that off and re-test if you do.
 
methanol injection??

im not sure if i have a methanol injection system or even what it is, where would I find it if i did??
 
Iac

The car always did the rough idle and ever since I cleaned the IAC it got a little worse, I am going to go buy that today and see if that helps but I hate dumping this money into a problem that Im not sure of.
 
You don't have methanol injection don't worry about that.

Deffinately change IAC. Did you change the maf electronis when you swapped mafs?
 
The electronics are attached to the actual MAF by two screws. It's what the plug goes into.
 
Actually, I re-read your post and my SC does the same exact thing for a second or two after I start it up. It eventually smooths out but it's running extremely rich.

Just so you know: Cam, Crank, DIS, MAF, nor Coil pack changed this symptom. I replaced so much because I had two problems at about the same time.
 
??

yea Im done replacing sensors, Im $300 into it and not difference yet! So do you have any idea why our cars are running to rich?? is it a gas thing?
 
did you actually change your mass air flow sensor or just the meter? Changing the meter itself will do nothing to make it better/worse you need to swap electronics.
 
Idle hunting will be due to something either lying to the EEC, or something outside the EEC control happening.

Possibly a vac leak. Could also be a overly rich condition, perhaps a leaky injector? I would check fuel pressure and monitor how long pressure will hold after you shut the car off. That will help knock down a fuel injector or fuel pressure regulator problem.
 
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