’82 High Idle Problem

My '82 all of a sudden is idleing at 1500 rpm. Car drives at 40mph without touching the gas pedal! Can a vacuum leak cause this? Any other ideas?

Thanks,

Dave

Dave,

It does sound like a vaccum leak to me.

Behind the left throttle body is a screwed in piece that has two nipples, remove and plug one vaccum hose at a time and start the engine to see if it makes a change in the idle. This will check the headlight system, the heater/ac system and the cruise control.

Also, the hose coming from the back of the base of the throttle body that goes to the MAP sensor may be bad.

Make sure the PCV valve and hose are good.

Check all vaccum lines or plugs on both throttle bodys.

Did it kick on the Check Engine Light? If it did, you need to put a Scanner on it.

Hope that helps,

Denny

Dave, if you don't find a vaccuum problem, it could be the IAC(Idle Air Control) motor not returning to rest.
It may be dirty with carbon, or it may have failed in the open position.
I would think a vaccuum problem is more likely, tho. It is possible that one of the base gaskets(under one of the throttle bodies) has burned a hole in itself.

Thanks Adam, I'll check those things out, but I think I'll wait a few days, it"s going to be over 100 the next few days. I'll let you know how I make out.

Last night I just did a visual check on vacuum hose connections and did not find any thing yet.

Dave

OK, I found it. It was a vacuum leak. the vacuum supply hose to the EGR solenoid valve came of the port on the TB base. Put it back on and the idle came right down to normal.

Thanks for the tips guys  

Dave

That was too easy, Dave...

Glad it was easy. Make ready for the next one!!!

Denny

For once an easy fix  I removed the air cleaner and there it was laying on the manifold, and everyone says vacuum leaks are hard to find

Dave