My idle keeps moving up and down from 1000 to 1500 in about 1 second intervals. What is going on?! It just started doing this today - before it would fluctuate more erratically but now it's more orderly. Help please!

 

Could be few things.

1. clutch switch needs to be replaced
(I replaced mine, and everything was good again)
2. air pump might be dead

Try turning on your A/C, does it stop it?

 

mine does the same thing, help!

 

No, the a/c doesn't effect it. Somone PLEASE help me, I am down on my knees!

 

Lower Intake Manifold gasket might be blown.

Have you had yours replaced yet? They came in paper form from the factory, later this became metal.

 

I diagnosed a car with exactly the same symptoms recently. It was the LIM gasket.

On the car I looked at, the idle would settle down if you pulled the electrical connector off the air pump. Of course, if you leave that off, your air pump will die.

To diagnose an intake manifold gasket, spray carb cleaner around the gasket. If it smooths the idle, you've got a leak. The lower LIM gasket is tough to get to, even for just spraying to diagnose it. I attached a long, narrow diameter hose over the spray tube and tied the other end of the hose to a piece of coat hanger so that I could position the end of the hose around the LIM gasket.

Good luck!

Jim

 

That's gonna be a PIA to change if you are planning on doing it yourself...BUT if you have all that stuff off already may as well have everything polished!

 

I had my LIM gasket changed too. I delayed it for over a year until I had to get it fixed in order to pass smog (high idle). It's okay if you don't fix it as long as the leak isn't too serious. It's an expensive job $800 if you do decide to do it. I spend more money basically getting hoses replaces and other things while they are all off of the car.

 

Actually, turning the A/C on fixes it! Do I really need to fix this problem cause I don't have any problem with running the A/C or heater when I drive (unless it puts some kind of extra stress on the engine).

 

I have this problem. Squirting some lube on the throttle body linkages and shafts fixes it instantly. Stays fixed for a few weeks or so.

I don't know if the lube is freeing up the sticking linkages or if it's sealing a small air leak.

 

my idle also fluctuates but its only right before its warmed up... once i drive it then i let it idle its fine..

 

ok what about me? i dont have an airpump i am single turbo and i replaced the lim gasket with a metal one when i did the turbo install. i have tried to adjust the throttle and i have sprayed everywhere looking for a vacuum leak but i just cant find one. i just cant figure it out. also my car will idle at 2k sometimes and sometimes it will be normal. then when it feels like being retarded it will idle hunt like a **** almost stalling and then reving again.....arg thanks for any help


john