i warm the car for one min, then drive it slowly until it warms up to normal temp,.....the problem is it idles at from 1.5 k to 2k rev.
even when i drive it for 15 mins,.......but when i turn off the car and start it up again, it idles normally at 900 rpm.
help is there somthing wrong with my car?

 

Check for anything causing the accelerator pedal, throttle cable, or the throttle linkage to stick. Rotate the Throttle linkage by hand and see if it returns freely. Keep an eye on the dash pot, it is that little canister that the throttle linkage uses for a back stop. It has a plunger on it, and if it is really dirty it may be sticky, or stuck. You can test it by pushing on it (the plunger). It should retract slowly, and return slowly.

Good luck!

 

its not sticking, any other ideas?

 

It could be dirty injectors. My BMW did that when I first got it. I ran some Seafoam through it and it ran fine after that.

 

It sounds to me like you have a pretty big intake leak. Try to quickly blip the throttle while the car is idling at 1500-2000rpm and see if it settles down. If it doesn't then you have a very big intake leak and you will need to do alot of dismantling to locate it. Good luck!

 

no it does not settle down when i blip the throttle,.....whats a good way to check a intake leak? how to fix?
thanks

 

Some say spraying a flamable solvent such as carb cleaner on the throttle body and around the gaskets will show a leak by the change in idle. Personally, I have never had this trick work on my FD, but maybe my solvent was not good enough. The amount of air that would be necessary to hunt your idle like it doing, is like Mach2 said, pretty big. There should be an obvious source for such a large amount of air. My guess is that it is still mechanical. Try looking at your fast idle cam, and try manually turning the linkage slowly in both directions to see if the idle improves. Where a glove so you don't burn yourself. Make sure that the cruise control cable isn't too tight, and well as the throttle cable. Both should have a little slack. If it is a leak, look for any hoses that may have popped off, and try rocking the throttle body and manifold to see if you have loose joint.

 

I've had the same problem with my 7, I tried to spray carb cleaner around where that upper intake gasket connects and no change in idle. I thought for sure it was the gasket before that. When I am comming to a stop (coasting) sometimes it's up around 2k then when I really do come to a complete stop it drops to 1.5k. Sometimes I notice it drops around 1k when just sitting.... but not usually. Dashpot maybe?

Thanks,
Chris

 

The reason why I think it's an intake leak is because when the car is shut off and then restarted, the idle settles at 900rpm like it should.
Pumped,
After the car is started and it's idling at 900 rpm, if you accelerate it does it get stuck at 1500-2000rpm? If so then you definitely have an intake leak. They can be very hard to diagnose sometimes. I once had the oil metering line to the rear rotor develop a crack in it which would cause the engine to suck air in through it. I replaced every single gasket and checked everything, and still wasn't able to find it. I probably would have never found it if I hadn't pulled the engine for a rebuild. Hopefully your situation is not the same. Good luck!

 

MACH2,
thanks for all ur help, .....when it is at 900 rpm, it dosent get stuck at 1500-2000 rpm anymore.