'88 p/u idles high

'98R/T · Dec 14th, 2005, 10:41 AM

The idle used to bounce around A LOT on my '88 D20 with the Z24I motor. I put new plugs, wires, cap, and rotor on it the other night and it doesn't bounce around nearly like it did, and it runs a lot smoother now too

What concerns me now is the RPM at which it idles. When the engine is cold it idles at almost 2,500 rpm then after it warms up it settles down to between 1,500 and 2k rpm.

All of my vacuum lines are connected but I've not checked the IAC valve yet.......that is my only guess. Is there something else that might be causing this?

Xeno · Dec 14th, 2005, 03:37 PM

That twice as fast as it should be.

Do you hvae AC?
To properly check vacuum hoses at home is to spray them with a rubber safe carb cleaner. Then if it changes in idle then you know it sucked up some carb cleaner.

Is there any code to read of the box?

'98R/T · Dec 14th, 2005, 03:44 PM

The truck has A/C, but the kid I bought it from said the compressor was bad and it doesn't even have a belt on it anymore.

I don't know how to read codes on this thing??? My other truck, I have a module that plugs in under that dash to read DTC's....don't know how to read them on this one.

Rubber safe carb cleaner you say.......I'll have to try that one night this week after work. I think it's a safe bet that all of the hoses are the original ones from '88

Have of them look like they're about to crumble and the rest aren't very tight on their 'port'.

Would a leady vacuum line cause the idle to be up THAT much though?