Suggestions?

[j_e_selner]

Alright so here it comes. I've got another high idle question.
When I start my car it revs at about 750 rpm than quickly rises to 1100 rpm and settles. I completely rebuilt the throttle body a couple days ago (which brought it down from 1300 rpm) and I can't seem to figure out what the problem is.

The previous owner deleted the EGR from the system (when I mean deleted, I mean it was actually removed from the car) so I don't know if that could have any bearing on the situation. I also have a slight exhaust manifold leak. don't know if that would contribute either.

suggestions?

[1stgen]

Originally Posted by j_e_selner

Alright so here it comes. I've got another high idle question.
When I start my car it revs at about 750 rpm than quickly rises to 1100 rpm and settles. I completely rebuilt the throttle body a couple days ago (which brought it down from 1300 rpm) and I can't seem to figure out what the problem is.

The previous owner deleted the EGR from the system (when I mean deleted, I mean it was actually removed from the car) so I don't know if that could have any bearing on the situation. I also have a slight exhaust manifold leak. don't know if that would contribute either.

suggestions?

Originally Posted by Gairloch

Unfortunately there are tons of possible causes for high idle. What you're describing goes well beyond the typical though at 2-3krpm.

I suspect that you've got a nifty neato air leak in there somewhere. Easiest way to check for leaks in the vacuum lines is to wave an unlit propane torch over them. If you find a leak the engine will rev. You can do the same thing with brake cleaner but I hate spraying that stuff on rubber parts.

If that doesn't yield anything take the intake piping off and inspect the butterfly valve in the throttle body. It could be damaged or there could be something preventing it from closing all the way. Inspect the throttle stop too to make sure it's allowing the valve to close far enough. It should be pretty tight but not actually touching the TB. The copper butterfly valve will actually dig into the aluminum neck of the TB.

If that doesn't work then while you have the intake piping off block the little hole in front of the butterfly valve. That's the ISCV (intake speed control valve) and if it's not functioning correctly can cause high idle. If you block it the idle speed should drop like it's going to stall. If it doesn't then you will want to disassemble it and clean it out thoroughly with brake cleaner.

I have stolen this quote so many times now..but it works..and fixed my high idle after I fixed the dirty ISCV.

[shimric]

That's usually the fix. When I first got my 2 it had terribly high idle. I ended up buying another motor because it imploded; It had a good iscv and it idled at 750 until I put the car into a tree. Then it was 0.

[traintech86]

Originally Posted by shimric

Then it was 0.

this sir is gold