Thread: low idle/engine dies while driving! need help ASAP please.

holy frickin crap batman!...

...

yes. problem again. after i recirculated the bov the car was running great for like 3 days, then i went and parked it, came out of del taco and power was gone. well one thing i noticed but had forgotten about was a loose/bad terminal connection on the power side of the battery. so i just got thru replacing both terminals, and power is back completely and the battery is only 2 months old, no lights or anything ever left on; so battery has juice. 590 cca's.

car turns on, fires right up, idles fine when im not moving. it drives fine and everything until i put it in neutral and let off throttle i.e. coasting to a stop, then it idles super low like 100-200 rpm, and sometimes even dies. builds back up if i step on the gas, but will keep dropping until i come to a stop, then it builds the idle back up by itself to about 750 - where it should be when its warm.

What could it be?

All my vacuum lines are on, no cracks or anything. no engine lights/codes. no sputtering or choking.

the only problems i can see with the car so far is what i've already stated: power steering pump bearings making a constant ticking sound because they've been dry for god knows how long, but that shouldnt cause that problem right?

please help!!

So far I've tried resetting the computer by disconnecting the negative battery terminal for about 25 seconds, but it didnt help.
I'm planning on testing the TPS soon with my DVOM.

Boost leak has been suggested as possibility but could that actually be the reason? This problem didnt seem to occur until i lost power from the battery.

Open to any and all suggestions. Dont make me tow this to the Stealership.....

Originally Posted by dsmguy142

does it happen only when its cold or when its warmed up as well? Have you checked out the ISC?

Does the car start right back up after it dies?

Is the battery keeping a charge? Could be an alternator issue....

Yes, battery is keeping charge, and car starts right back up after it dies. It doesn't die often, but always does the low idle.

I have not checked out the ISC, because I'm not sure how to do it. Couldn't find it on VFAQ...all I can think of is that I think the ISC is based on resistance. If someone can tell me how to check it out, I'll do it.

Seems to do it whether its cold or warm.

I tested 1,2, and 3 but couldnt fit my hands in there to test 4, 5, and 6. the ones I tested were all in proper range.

I tested the TPS and its working properly as well.

I was told today that by disconnecting the negative terminal to battery (to reset the computer) actually makes it have to relearn, and that may be causing my idle problem. To make it relearn I was told to let the car sit idling for ten minutes then drive stop and go for another 10 to 15 minutes. I'm going to try that in about 45 minutes from now to see if that corrects it.

Is it really necessary to test 4,5, and 6 on the ISC? Would there be a decent chance that 1,2,3 can be good and 4,5, or 6 are bad?

Sweetness. It's fixed. Just did a 30 minute test drive.

I'm not 100% sure what the fix was but this is what happened:

Went back to check the 4,5 and 6 on the ISC, when we looked at it closer (we removed the battery so we could see the whole thing), one of the pins was bent. I'm not sure if it was like that before we tested the first 3 pins or not. So thats why it's not the for sure fix.

We tested the other pins and the ISC is good. We pushed that pin back into place, reconnected the battery and everything. Let the car idle for a little longer than 15 minutes, then we went and drove it and everything was perfect. We drove for almost 30 minutes both in stop and go neighborhood style driving and city driving. Drove perfectly.

My bet is that when we had the motor apart for a rebuild, we rushed putting all the connections back and possibly bent that pin. Or the computer relearned when we had it idling for those 10-15 minutes.

Idle Speed Controller

A place called Crebotech used to sell refurbished ones, but i doubt they are still around.