BuckeyeZ28

Recently had the old opti take a dump (right on schedule) and I had to tear it down and replace it. While doing it I removed the intake manifold and replaced the gaskets, and removed my AIR pump. Now I have it all put back together and it fired right up, but after 1-2 mins of running it starts to sputter and idle up (around 1500) and then idle down (200-600 just sputtering and barely running) Checked all my ignition stuff, fuel pump is good, im thinking its a vacuum leak. So what opens up after that amount of time that makes it suddenly want to die?

ss.slp.ls1

iTrader: (36)

Have you hooked up a vacuum gauge to the intake manifold to verify that it's a vacuum leak? As many will tell you, double and triple check your plug wires.

BuckeyeZ28

Negative on the vacuum gauge, and the plug wires are good. It runs normal as can be if you go WOT before it starts sputtering, but afterwards its just horrible. What about O2 sensors... is there a way to rule them out short of buying new ones?

ss.slp.ls1

iTrader: (36)

You need to use a scanner that displays real time data and verify that the o2 readings are oscillating within the full range.

One quick and dirty way to find a vacuum leak is to use a can of brake cleaner/carb cleaner and spray it around the perimeter of the intake manifold sealing surface and around the intake elbow after the MAF. If the idle goes up, you've found your leak.

BuckeyeZ28

Ok... so does anyone think this is a vacuum prob or something else? Ive check and double check everything I can think of and it seems like everything is good. Would removing the EGR solenoid have anything to do with it?

ss.slp.ls1

iTrader: (36)

Only if you just unpluged the vacuum lines to it and left them there open and didn't cap off the vacuum port on the intake manifold that ran to the solenoid.

BuckeyeZ28

There plugged... same with the egr/air in the rear of the manifold.. you can hear that vacuum leak really bad too but i just cant find it.. looks like i will take it to a shop..

ss.slp.ls1

iTrader: (36)

If you took off the manifold, then it can be in a number of places.
Make sure all of the little metal nipples are plug off or being used.
Make sure that the PCV hose is there and routed correctly.
You didn't forget the donkey dick in the intake elbow did you ?

Here are some pics, make sure everything is there or plugged off.
http://shbox.com/1/pcv.jpg
http://shbox.com/1/egr1.jpg
http://shbox.com/1/evap_sol.jpg
http://shbox.com/1/tps.jpg