Rough Idle

[SmoothSteve3]

Hey guys-

 

Ok, my 3.1 MPFI has had a rough idle for quiet a long time.......she doesn't really die, just kindof sputters a little bit.......especially after she's been running for 5-10 minutes. I've cleaned the throttle body, changed IAC valves......and I still just cant seen to figure out whats doing it.

Any suggestions? Thanks!

 

SmoothSteve3

1990 Chevy Lumina

3.1 Liter V-6

Ride on White Lightning

[Redfox340]

Could be any of the following:

* faulty / mis-gaped plugs

* old / resistant plug wires

* clogged EGR valve

* faulty fuel injector

What has been replaced lately?

Any Service Engine Light's?

 

- Erik

[Slade901]

Do an Idle Re-learn

 

Is your battery 3 or more years old? My car does the same thing and sputters all the time approx every 15 minutes and sometimes does in the stop light. My battery was old 3-4 years and even though it is getting charged up close to 14 Volts when the engine is running but its capacity itself is deminished.

 

Note I have done an Idle Re-learn many times with the old battery and still does the same thing.

I've done an Idle Re-learn with the new battery and my car does not sputters anymore and it does not die in the middle of the stop light.

 

What I have noticed is that when I'm running my car Idling and trying to do an Idle Re-learn. The battery is almost drained completely when the radiator fan kicks in and so the alternator is not able to keep up to charge the battery and the old battery's Reserve Charge has diminished and not able to hold larger Reserve Charge.

 

It's like a rechargeable battery which in time it is not able to hold longer charge and it dies quickly.