i have a 94 GC V8 and a few weeks ago i noticed that there was WHITE smoke coming from tail pipe. so thinking the worst i pulled the cylinder heads (with the help of my father in-law) got everything back together with NO extra parts (hell yeah) but now me problem is that it ran GREAT for the first two days or so and now it starts and just dies but if i keep my foot on the throttle for a little bit and let it warm up it will idle some what ok. my first thought was that it was a vaccum line so i got under hood again and checked ALL the lines i found the 3 lines on the pass. side were lose (didnt fit tight) so thinking that was my problem i fixed the lines slammed the hood and off i went. now its STILL doing the same thing i am at a loss i dont want to get start throwing parts at it hoping to try to fix the problem nor do i want to take it to a shop just to have them say it didnt do "it" for us (and oh by the way that will be $300) so im asking if anyone has an idea of what it is to post it

thanks drew

 

did you check for a leak around the plenum? and double check that all the wires were reconnected including the grounds?

 

Yes the intake manifold is tight and ALL the wires plugged in

 

How is your oil pressure?

 

Oil pressure reads 30 psi when it does idle and 60 psi at 2000 rpm (on the interstate)

 

Could be an EGR issue on your '94 GC V8. This explains/shows how to test it, and replace if needed:

 

Ol blue its not the EGR I just tested it and I'm still at a loss

 

Update after I tested the EGR it smells real gassy kinda like its running rich but I have no way of testing if it is also if it was running rich I don't think it would die on me I think the rpms would rev higher

 

Ok so I finally got my wife to help me so I had her start it while I was in the engine bay I heard this massive sucking sound I got the air cleaner off just in time to see that the butterflies on the TB were shut all the way it was still making that noise tell I opened them but it still died what could that be

 

Mass air flow sensor? is check engine light on?

 

sounds like the same type of issue I am having. I didn't have a cel but when I checked codes it says running to lean. I checked the fuel pressure and I barely can get 10psi.
Might be something you want to check to if nothing else eliminate.

 

Nope no check engine at all.....I did change the fuel pump relay I don't think that was the problem but it ran for bit and of course it was warm when it ran earlier......I did the IAC clean up today it wasn't that dirty but I also decided to take the TB off and clean that up too after it did the same thing that's when I changed the fuel pump relay out.....just thinking out loud here now could it be that the daifram in the EGR valve is bad but it tested fine and if so how would I test it to see if it is bad

 

Maybe the computer is taken a crap? try putting dielectric grease on the connectors.