Idling issue

[FreedS4]

I've developed an idle issue over the course of the past week. On start up the car jumps up to 1250RPM or so, then drops back to 500RPM and sometimes acts like it is going to die, but then jumps right back to 750ishRPM. Then it idles relatively smoothly. When I'm driving it around and push in the clutch, the idle drops down again to 500RPM and then climbs back up to 750ishRPM. Also, the car seems a little jerky if I'm in gear and barely giving it any gas. Another point of note is that it seems to get better, meaning not as much of an RPM drop when I let off the gas in neutral to almost no drop at all, when the car warms up. Any ideas? Thanks in advance.

Chris

[JMPAuto]

Check for air leaks first...

[reelop19]

More specifically check you boot (that black curved thingy coming off the air filter). Oh and if you have an aftermarket intake that could do it too. I replaced my boot and put in a stock intake and she purrs real nice now.

[FreedS4]

On start up, it's acting like it wants to die even more now and hovers around 500RPM until it gets nice and warm. Ran a smoke test today, no leaks. ICV has been cleaned and appears to be working. Any other thoughts?

[jlevie]

See your thread in General Technical

[FreedS4]

See your thread in General Technical

Thanks Jim, I appreciate your help.

[FreedS4]

On start up, it's acting like it wants to die even more now and hovers around 500RPM until it gets nice and warm. Ran a smoke test today, no leaks. ICV has been cleaned and appears to be working. Any other thoughts?

My TPS wasn't reading any ohms until it hit the idle stop and sometimes didn't register ohms at all. I've adjusted it so it's reading accurately now and my idle seems a litle more stable and doesn't want to cut out when I let off the gas abrutly. The RPMs also don't drop as far down as they used to when I let off the gas. The only thing I haven't checked is the cold start-up and it's tendency to almost die at first. I'll let her cool down fully and check it out, but all signs point to it being fix, or at least better. Thanks for all of the help.

[FreedS4]

My TPS wasn't reading any ohms until it hit the idle stop and sometimes didn't register ohms at all. I've adjusted it so it's reading accurately now and my idle seems a litle more stable and doesn't want to cut out when I let off the gas abrutly. The RPMs also don't drop as far down as they used to when I let off the gas. The only thing I haven't checked is the cold start-up and it's tendency to almost die at first. I'll let her cool down fully and check it out, but all signs point to it being fix, or at least better. Thanks for all of the help.

Just went and started her up and she's having the same issues as before on start up. Jumps up to 1000ish RPMs, then drops to 500ish RPMs and settles at around 600-650 RPMs. If you give it some gas and then let go, it drops to 500 RPMs or lower and almost dies. The idle seems a little more stable when she finally gets warm, but when cold, not so much.