Thread: EGR issue on LT1 Firebird

So my egr is not working on my wife's 94 LT1 firebird. If it run a vacuum line straight to the egr and suck on it with the car off it will draw the erg fully open and stay there if i put my finger over the end of the vacuum line. But when i start the car it immediately goes back to closed. .

I also tried hooking the vaccum line straight from the egr diaphragm to manifold vaccum but no change in the engine. However if i push the diaphragm open by hand it will bog the car down.

Unfortunately the egr cost 70 dollars and has to be gotten from a v8 camaro or firebird. neither of which are in the local junkyard so be for I spend the 70 dollars I was looking for a little more input. It seems so odd that the valve will stay open when the engine is off but not with it running.

why not just delete it?

Because the car isn't getting a code for the egr not working so I keep getting knock retard when it's driven on the highway. (And that's with 93 octane)

I replaced the egr since i could feel vacuum at the egr vacumm solenoid when i actuated the EGR. It works now and no more knocking so I'm happy. Still curious why the EGR valve would hold open without the engine running but not with it running.... beats me

Prolly something wrong with the diapharm on the inside. Kinda weird.

My 94 silverado with the 350 had that issue, did the egr and solenoid.