I've been having some idle isuues lately. My car starts and runs fine. The problem happens when I'm braking. When I'm slowing to a stop, between 5-10 mph, my idle bounces between 500-1000 rpms. Almost to the point of stalling. It hasn't stalled yet. Then it idles normally when I come to a complete stop. I'd like to get this figured out before I drive 3 hours to go home from college tomorrow. Thanks.

 

Have you checked your vacuums? Also, how's your ignition wiring/timing? MAF sensor still good?

I'm currently trying to solve mine, and am slowly seeing results. I've replaced my ignition wires, spark plugs, fuel filter (thought it was a fuel pressure issue), air filters, and going to replace my dizzy cap/rotor today. Process of elimination seems to be working well.

Unfortunately it's cost me over $150, but I need to replace all the bolt-ons regardless. I'm sure someone will give you a better solution than I. I'm still learning as it is. I hope what I've said has helped.

 

Well, I replaced my spark plugs and wires less than 10k miles ago. I thought it could be fuel related, but at highway speed it runs great. I'll have to check my vacuum lines later today. Thanks for the hints. Oh, the MAF sensor was replaced less than two years ago. I'll have to check my records on that though.

 

Yeah, mine runs perfectly at higher speeds, but once I hit around 10 mph, it begins to stall. My ignition coil looks horrible, and the repair manual I have says it could be that.

Odd how many people have had this problem so recently, a twisted plot by GM to get us to buy the new Camaro? haha!

 

check the idle air control motor. open it up and clean the housing because it will be very dirty. If the IAC is bad you will see the plunger thing fall out.

 

I haven't cleaned out the IAC in a while. I'll do that before I run some errands today. I'll post the results later tonight.

 

I'll have to check mine, too.

 

Ifit only happens when you have the brakes on; its vacuum, the brakes draw enough vacuum to nearly shut an engine off if its leaking.

you have a vacuum leak.

 

Thank for the advice Gumby. I took a look at my vacuum lines and there were a couple rotten ones. I replaced them and it hasn't had a weird idle since. I think the culprit was the vacuum line from the power steering pump which connects below intake manifold.