What's up with my idle?
 

Hey guys,

Sometimes...yes...sometimes, my idle is hunting...

Usually, the car starts up great and idles perfect (after about 5 seconds), but sometimes lately, the idle hunts up and down (1200-700-1200, etc) for about 15 sec or until I step on the gas a bit. After that, never a problem.

What could this be? I'm planning on refreshing the complete fuel system and vacuum lines, so hopefully that cures it.

Any ideas?

It sounds to me like your idle stabilizer valve is gunked up. It's located underneath the intake manifold, but can come out with some manual contortion if your fingers are not too big.

Pull it out and give it a good cleaning with WD-40 or some solvent. Make sure it's dry before you reinstall it and see if that improves any.

You could also try cleaning up your engine grounds. There's a quick test for this - start the engine up and then clamp a booster cable to the engine and a decent ground or to the earth (ground) terminal of the battery (if it's mounted in the front). If the idle improves then you know you need to clean up your strap points.

Interesting....thanks for the tip.

I noticed that my ground point is corroded (a little) on the engine block and my idle gets erratic when I turn on the rear window defroster - I've been planning on cleaning up that ground point when I replace the vacuum hoses under the manifold (soon). But, I'm going to try your suggestion just for kicks - it certainly couldn't hurt.

Vern

I installed a Wilk PP2 2 weeks ago & now when the motor is cold, the idle hunts for about 2 or 3 mins. until warmed up.
I know that the chip ignores the O2 sensor, & that was probably hiding whatever problem was making the cold idle hunt
is there any easier way to clean the ISV than taking off the intake manifold to remove the ISV?

You can remove the ISV without pulling the intake manifold. It's a bit@#, but it can be done unless you have large hands.

Thanks for the tip, Dark Skies.

My idle did that so I ran some carb cleaner through it...lots of smoke but cleared it up after a few smokey minutes.

Otherwise, you have a vacuum leak or a bad ground as stated.

Thanks guys for all the tips. I'll get busy with it and start checking the ISV first.

Interesting. What is the process for this.....where can I open it up to run carb cleaner through it?

You can disconnect the hose that goes from the intake manifold to the ISV and shoot some fluid through there, but it's best to pull the whole thing out and rinse it out well.

Here in California, to cut down on emissions, the fuel suppliers at state regulation will re blend the gas with ethanol during the winter. To get better firing and cleaning out the left over deposits, you need to run a few tanks of Chevron fuel or a bottle of "Techron?" to your fuel occasionally. Other states may do the same but I am not aware.

Hmmm...that might not be a bad iea.

Also, I have the feeling that when it's parked with its nose down, it fires right up, but when parked nose up, it cranks about 5 times...Does that give anybody any clues?

I'd try the Techron first. And then see if for some reason your fuel pump pressure is light if the techron doesnt work. I think you'll see a vast improvement if you switch to Chevron though (Or the techron additive)