Hello,
I have a 1991 Chevy cavalier. When I start it the car will start up and then immediately die. I found that when I take the hose off of the pcv valve it stays running but idles much louder. I replaced the pcv valve assuming that it was clogged up and then I put the hose back on and I’m still having the same problem and it will still run with the hose off. When I turn the car on it will stay running if I rev the engine but I can smell gas. I’m either thinking that the carburetor is running too rich or something w the fuel pump? Any ideas?

 

Sorry if this sounds mean , it's not meant to be , but this is not the forum for you .

This forum deals exclusively with 1982-1992 Chevy Camaro / Pontiac Firebird cars , which are the "Third generation of the GM F body" car , hence the name "Third Gen . Org" .

On an outside guess , not knowing anything about your Cavalier , it sounds as if your carb needs a rebuild , especially that the needle & seat are leaking causing excess fuel to be dumped into the manifold .....

 

A 91 isn't going to have a carburetor. That's going to be TBI or MPFI.

Pulling off the PCV valve hose is introducing "pirate air" under the throttle plate and bypassing the idle air control valve. Possibly the IACV has failed and is not opening to allow air in at idle.

But that is a GUESS and guessing is not a substitute for proper diagnostics. It sounds like you are way out of your element and should seek some professional assistance.

GD

 

Good catch GD , when the OP mentioned a carb I didn't think twice about the 1991 part of the discussion , I just went with the most common reason a carb would suddenly run rich , a stuck open needle & seat (or a sunk float) .