I searched on this topic, but most people's problems have to deal with cold starts etc, not really my question.

My car warms up perfectly at 1500 rpm and then slowly comes down to about 800-50 rpms. The car has a rock solid idle here, no problems whatsoever. However, after I have warmed up the car and drove around for awhile and park it for say 15 min, when I go to restart the car, it starts fine, but wants to drop to about 500-600 rpms, almost stalling, and then settles on about 650 to idle at.

After I get moving, the idle jumps back up to about 850 and stays strong. I have about 7k on the car, and was wondering if this could be low compression, or just a bad set of plugs. The car did sit for about 8 months on the dealer lot until I picked it up. This could be somewhat normal, but I really didnt find anything when I searched.

 

if you're stock take it to mitsu. it could be something really simple, or not. i'd say best to let them check it out if your warranty isnt voided.

 

Yeah, I am stock(well, hopefully stock enough ). I was going to take it by there in a week or two anyway because the fabric on my seat is coming apart, and my brake calipers look horrible(paint fading) I will tell them about it, but I was just wanting to get an idea of why the idle is droping like that. It's a little werid because of when it happens. I would think that if it was low compression, it would happen whenever the car started, not just after it was already warmed up. I may just have a crappy set of plugs or a vac leak somewhere.

 

It could be what you said or maybe even a faulty TPS. Let us know what Mitsu. says. I'd like to here what they say about your seats because my driver seat fabric has pulled away from the seat and looks all wrinkled. Good luck

 

Do you have the Grounding kit on your Evo?

 

Yes, I put an hks grounding kit on there probably within the first 1k miles of owning the car. Other than for the first 30 sec to a min. after I restart the car, the idle is fine. Its only after the car is already warmed up that it happens.

 

This may or maynot have anything to do with what you are describing. My 95 Eclipse was doing the exact same thing. I would start it in the morning and drive to my first stop on the way to work, this would be about a 20 min drive. I would get out of the car for about 5 to 10 mins then get back in and start it up. I twould run perfect up until the first stop, then after restart it would run rough whenever I had to stop at a light. Sometimes it would even die and not restart for a few mins. The problem was caused by my ECM (Computer) was not grounded to a chasis ground. I don't know what is had to do with the heat in the engine compartment, but it only happened once the car was warmed up. I found the spot that the ECU was supposed to be bolted to and reattached it. This is what I get for buying the car used, but after it was bolted down, the problem never accured again. Might be worth a check, will only take you a min or so to look under your hood.
Jay

Sorry for any spelling errors, I have to keep one eye out for the boss! LOL!

 

Thanks shado, I will check that and see what it does. I am going to go over my grounds and check the vac hoses too in a hour or so.

 

Take the kit off before you roll to the dealership, that's my advice!

 

Haha, yeah no kidding. It's a part that they themselves sell, but since its hks and not mitsu they may try and void me. I should spraypaint it red and write in ralliart with a yellow marker. It would be pretty sad to get voided for a catback and some grounding wires, but I dont think that will happen.

 

It will, if you take it in like that.

Believe me.