Ok, after my car runs for about five minutes or so the car will start to idle from 1000 to 2800 just up and down quickly. If im driving the car it dont do it but when i stop it will start to jump again. I havent driven the car for a while and it did it before but wasnt as bad. Im going to check the thermastat tommorow but what else should i try to look for? Thanks

What's your setup? Explain yourself, or better yet your car - is it stock, what aftermarket parts do you have. Have you recently washed or cleaned your engine bay? It's very easy to get water or soap up into your distributer. That'll screw with your idle and happens all the time.

vacumn leak, that what I would check if you cant find one I would check the brake booster for a leak

Mods are..
B18a, intake, header, stage 2 crower cams, cam gears, p30 pistons, type r transmission, and a safc. Could it be that the thermostat is stuck open maybe? I am going to check it out again tommorow so well see. No i havent washed the car recently but it has been sitting for about 5 months and i am in north dakota so we have alot of snow right now but i doubt that caused it. It only starts to idle weird after 5 minutes or so, never right away.

Why do you think it would be your thermostat? That helps to control the flow of coolant/water in and around the engine. When checking for idle you would want to check (correct me if I'm wrong mods) spark, fuel, and air. One of these three will most likely be your culpret (sp?). If your thermostat needs to be changed, well change it. It takes all of 20 minutes start to finish.

Otherwise, check:
your dizzy, (replace if old) make sure there's not humidity of some kind in it.
your plugs and wires, when was the last time they were replaced?
your air filter, make sure it's not clogged with salt and crap from the road.
your vacuum lines, like b18b-hb said, that can screw with things too.
Also, your fuel filter, no fuel = no go, also like all of these things, way easy to inspect and replace if needed.

Good luck, I hate crap like that. Let us know how it goes.

I'm pretty sure its coolant level.

ORrrrrrrrr the SAFC...

The plugs, wires and air filter were all changed last summer, but it wouldnt hurt to check them out. It just really sucks because my car is louder than most and when i get behind or beside someone at a red light or something they think im just being stupid by reving up the motor. I work all day tommorow but have the next day off so that should keep me busy for awhile. Thanks for the help guys

I topped off the coolant just like 4 hours ago and no change at all, it was a little low but not bad at all. Im gonna flush it out on sunday and refill it and see what happens. The thing with the SAFC is that early last summer the car ran great then i put it away for a while, the settings never changed so why would that cause it to idle irratically now? Not being a smartass but seriously why would that change it and cause the car to do this.

i dont know anything about safcs but are the connections soldered in or like twisted... or what? does it use a harness or of some sort or are the wires hardwired?

check the connections for the SAFC. Since its a fluctuating idle i'd be willing to bet its an electrical issue.

Maybe the IACV is bad, when you flush the system clean the IACV and make ssure the FITV is not out of adjustment.

what he said...

Good luck checking everything.

I never thought about checking the safc wires, ill have to check that. Thanks

still fighting the problem, really I would check for a vacunm leak just my two cents again

ya that really sounds like a vaccum line. just replace them all cost between 10 and 20 bucks. just need the sizes. and make sure to do it one at a time..

try cleaning out the iacv

PostPosted: Mon Feb 19, 2007 1:40 am Post subject:
try cleaning out the iacv

what he said or maybe your TB???

have you checked to see if the o2 sencer is bad? sometimes that could cause the car to go into limp mode.

you have a bubble in the coolant system im guessing. you have to breed out the air in your coolant system.

Just a thought, if applicable check ur exhust if u have a cat converter and its going bad it could cause enough back pressure to jack with ur idle at idle.

try cleaning off ur IAC valve and try adjusting the idle screw a lil bit

Its could be youe idler air control valve sticking because of being dirty.