so no luck so far trying to find leak, im only getting the p0507 code now

 

update needle goes from 15-20 quickly on vacuum gauge and raised rps to 4k
click on pic to play vid

 

Last time I witnessed a needle jump like that at idle the truck I was using the gauge on, it had a flat cam. Now the needle didnt smooth out as I revved the engine it kept bouncing. I am at a loss here to tell you why yours is doing this. Old thermactic valves could do this but these cars dont have any of them.

Have you tried the old starting fluid on the intake gasket seams trick? Or how about the injector O-rings? Just a couple of ideas that come to mind.

Massey

 

Is your engine stock? A cam with more overlap will give you bouncy vacuum at idle.

 

Stock engine besides headers and cai. I used carb cleaner to try to find leak.

 

The motor is getting air from someplace to run that fast. Have you tried pinching off or disconnecting Vacuum lines? If that all checks out your back to the air getting in thru the throttle plate or IAC motor.

I would not expect to see the needle on the vacuum gage do that from just a vacuum leak. Like Massey said that is normally a valve train issue. The real test would be with the car in gear or under light load. I have run vacuum hoses into car and driven them many times. If you needle is jumping like that under a light load something major is going on.

 

As soon as i give it just a tiny bit of gas the rpms just to about 4k and hold there for about 5 secs. they then go to about 2k. A lil later they will will go down to 1.5k. Im suppose to idle at 1k or at least thats how the car used to idle. When i first start the car for the first 20secs or so it acts fine. Im going to take apart trottle body to see if its all good. I have a spare gasket.

 

My vote is sloppy valve guides: http://autospeed.com/cms/title_Using...3/article.html

 

im beginning to think you have a rich conditon and when you open the tb a little it lets air in and the idle jumps way up. test your evap system and it may be worth it to have the injectors tested and cleaned.
https://camaroforums.com/forum/lt1-lt4-tech-9/testing-evap-system-51219/

 

So its been a while since ive updated this. Part of the reason is because ive been busy working on others cars. So a buddy came over with a 98 3.8 so i thought while he is here wel just swap sensors. Swapped the maf and no change. I swapped the iac valve and no change. When i unplugged the iac and left it unplugged i noticed the rpms dint hang anymore it just idles high like it has been. Any ideas?

I should also note that the rpms dont dont hang as high or long since i cleaned the throttle body and installed new gasket.