Magnum '82

I have a rough idle(warm & cold)-engine idles about 700rpm and surges to 750rpm. This cycle repeats about every 1.5-2 seconds. Also, when it does this the engine shudders and then smooths out. Could this be from misadjusted lifters??? One more thing-when cold, the idle is fast. I run it for a minute or two before I put it in gear otherwise it is rather harsh dumping it in gear. :banghead:

Jack71

I'm no tuner, but changes at idle can be caused by vacuum advance problems. But, hopefully somebody else will chime in too.

Magnum '82

ttt

ROD NOCK

My first suggestion is to check for vacuum leaks. As a leak will cause a lean condition and surging. Disconnect all hoses and look for cracks/causes. If a hose checks out fine, then plug it temporally, start eng to check if prob exists. If gone, you've found the prob in the accessory that the hose connects to.
Leaks can occur in a mulitude of places. Intake gskt, carb gskts/base, dist vac adv. or any # of accessories plugged into the intake sys.
Don't forget to check the EGR for leaks, or being stuck open.
As for your fast idle when cold, this is a normal part of the choke operation. There's a spec for this fast idle rpm. It's best to wait till fast idle resides before shifting and drive away.
I highly suggest you purchase a factory service manual for working on your car. It will give you much of needed info.
Good Luck -Rod :chevy