I've recently intsalled some crane stage 2 cams, dual valve springs, ti retainers, adj cam gears. And once the engine is at normal operating temps the idle is messed. I figured the cams/springs just needed to settle in a bit, so i broke it in then took it to the dyno and tuned with a vafc2, but the problem is still there.
It will jump around quite a bit. It will bog down and almost die and then rev up to 1500rpm then bog back down and almost stall.
Then after a few minutes of this it will idle perfect. I've cleaned the IACV, new FITV when i put on the bigger t/b, new PCV, checked for vacuum leaks.
Is it possible that the o2 sensor is faulty? Would a faulty o2 cause a messed up idle like i have described?
The car runs mint otherwise. Pulls like stink up top but won't idle at all.

 

check how much vacuum you are pulling.

 

what should it be so i will know when i do so.

 

25 - 22" on with stock cams so if your less then that that is probably your problem and will need to fix your this problem with some tuning.

 

ok thanks man. I'll check that out tomorrow.

 

did you adjust your valves? that maybe your problem..

 

yeah like 3 times already. My g/f bought me a timing gun and vacuum pressure guage for xmas. I don't think the timing's been checked with a timing gun since the install. I also need to try another iacv valve just to be sure. I checked mine out and there was no crap on the screen.