Chevy & GMC Vans

You wont see a problem if its an O2 sensor until its warm. It will use the base fuel table and should run fine although likely a little rich. I bet it turns out to be something that has everyone slapping their foreheads.

I bet it turns out to be something that has everyone slapping their foreheads.

your exactly right , it will be something so stupid that we're just over looking it .

Just a shot in the dark, but perhaps you have a leak at the intake manifold gasket or throttle body gasket. How do the plugs look?

intake gasket was just replaced (one of the last things he did ) & the plugs looked good when he had them out to do a compression test . plugs all seemed to be burning evenly & clean , no soot or carbon build up .

keep the suggestions coming , eventually someone will think of something we have not .




And dean , i'm doing everything i can to keep him from blowing it up , please don't give him any more ideas !!!

Jim if you do happen to find a witchdoctor send him this way , we'll try anything at this point .

I've thought about burning it, but a 1/4 stick inthe gas tank would be cooler to see.

What brand fuel pump did you put in??.Any chance you are seeing the pressure,but not the volume??.Did you straight edge the intake to check to see if it was warped??.Let say it is leaking to the inside and not to the outside.You could spray it to death and it wouldn't show up.

The only thing that was noticed is that the EGR valve has vaccum at idle when it shouldn't untill the RPM's are brought up .

any idea's about that ??????

bump !!!! any ideas ? anybody ?

I know when we were in PA wheeling one time and Bill came over to see us, his van wouldn't idle to save it's life. We pulled the EGR and found it was stuck open with some carbon chunks. Seems to me that your should be closed as well and the vacuum seems to be holding it open. Pull the vacuum line off and try it. Then if it works, just gotta find which lines are crossed or why it's pulling vacuum at idle.

i'll talk to him to see if hes tried that or not , but i think he has , i know hes had the EGR off a few times .

It ran the same with the egr unhooked, but according to my cousin, the egr is fine. He also said that the little amount of vacuum that it has, it wouldnt cause the problem im having.

I think your van has a positive back pressure EGR valve and EGR Vacuum Solenoid. You might wanna check out the solenoid. Its what sends vacuum to the EGR valve.

What effects would a bad EGR solenoid have on the motor? would it effect the idle as bad as it is ?

It could maybe allow vacuum to the EGR valve keeping it open and allowing excessiev flow at idle.

nope , not the egr solenoid or the egr itself . theres not enough vaccum being drawn to really effect anything . vaccum lines area little crossed but thats no biggie , an easy fix . but it still won't idle & dies when put in gear .

but it still won't idle & dies when put in gear

You know, I had a 91 Mazda MX6 that did the same thing. I doubt it's the same culprit as here, but I'll thow it out there any ways...
Every time I came to a stop, I had to throw it in nuetral so it wouldn't die, as soon as I put it in gear, I had to gas it so it wouldn't stall. It turned out the rubber intake tubing leading to the MAF was cracked, not enough that you could tell just looking at it, but when the motor torque'd when it was put in gear, the crack opened up causing a really lean condition and it stalled. funny thing is it would run in reverse just fine. That's because in reverse, the motor torque'd in the opposite direction sealing the crack in the rubber intake pipe.
Like I said, probably not the same culprit because were talking about 2 different vehicles with 2 different intake systems, but maybe it'll help get the juices flowing in the brain and might help you find your culprit...


How are the motor mounts?