Jump to content

HELP: Bad idle speed fluctuations.....car almost dies???


TeeJay3800

Recommended Posts

May battery died, and I put a new one in the other day. Ever since then my idle speed has been fluctuating badly. It idles fine in and out of gear when at a rest. The problem occurs when the car is moving at a crawl. For example, when coming to a stop at a stop light, the engine speed surges significantly. It sounds like it may die at the low end, and at the high end of the fluctuation, its enough where I have to step on the brake harder to keep from rear ending the person ahead of me. Once in a while it will actually die when backing up after the car has just been started.

 

I have already done the idle relearn procedure described on 60v6.com, but it made no difference. What happened to my car when I changed the battery? Any input is appreciated!!

Link to comment
Share on other sites

Since you disconnected the battery your ECM lost power. Do an idle relearn and it should fix itself.

EDIT: Sorry I didn't see you already did the relearn.

Did you arc the battery when installing the new one or anything?

 

- Jeff L.

Link to comment
Share on other sites

No arcing that I know of. We tried charging the old battery, but the car would still not turn over (only a click when I turned the key). So I installed the new one and that was it.

 

The problem happens as I'm coming to a stop, and then for the first few seconds after I stop. Once I've been at rest for a short time, the engine speed settles down and sounds normal again.

Link to comment
Share on other sites

My Lumina did that the day I ran outta gas..there must have been a bunch of air in the fuel line or something..however I experienced the same thing as you I think. Acceleration was good..idle would get normal after a few seconds(maybe 20secs)..but if in stop and go traffic the revs would bounce all around right?

Well..this was when I did the idle relearn..and after a few days the problem stopped all together.

I've alos heard the ecm is suppose to relearn everything after you drive it for a bit. But I didn't like driving my car when at a red light it was bouncing everywhere in the revs..and it sounded pretty bad...

Free bump for anyone else!

 

- Jeff L.

Link to comment
Share on other sites

UPDATE: I've realized that it only stalls when in gear. I'll come to a stop and the idle speed will be going up and down and eventually die. However, if I pop it in Neutral, it will run like normal.

 

Why would the idle fluctuate and eventually die in Drive only? Torque converter issue, or IAC?

Link to comment
Share on other sites

The SAME EXACT thing happens to my Lumina anytime I disconnect the battery. I've done the relearn thing and it makes no difference. I took it to a mechanic I trust and he suggested the Idle Air Control Valve. (IAC) I changed it and it worked, so I took it back to him to see what the problem was rooted from. He said that my car has a short in the system so anytime I disconnect the battery than re-connect it, there is a surge in that circuit and it will blow out the IAC. Trust me, I don't disconnect my battery anymore after my 5th damn IAC.

 

Your car may have a short but idk, I'd suggest the IAC though. When you replace it, the car will run funny until the computer learns the new IAC but after about 10 mins of normal driving, the car will be fine.

 

Now.. here's the kicker. I went to autozone and tried 9.. yes I said 9 IAC's... 3 out of 9 of them worked. (this is over a span of 6 months):verymad: I went to Advance Auto Parts, and the very first one I tried worked like a charm. It's a little more expensive there but it's worth it.

 

Let us all know how it turns out.

Link to comment
Share on other sites

You said that you changed the battery. Check/clean all of the connections, and also, check the aux. battery terminal connections. It could also be a faulty ground connection.

Link to comment
Share on other sites

My belt tensioner isn't the best, but I don't see how that would cause idle fluctuations in gear only. Also, battery terminals look good and it is grounded properly.

 

I believe the cause for this is I have a vacuum leak. There are several vacuum lines running near the battery, and I probably broke or unplugged one when I was changing the battery. I'll check it out and let ya'll know.

 

Thanks for the respones :)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...