87 Camaro Dude

Hey guys, my 2.8 MPFI is running a little rough when cold and I figure I'd pick your brains on what it could be. The engine runs fine when it's warmed up, but has problems staying alive when it's cold. I'll have to keep giving it throttle to keep it running. I probably won't get a chance to fix it soon, just thought you guys could help narrow it down to what it could be. Thanks.

ex-x-fire

I'd start by checking the fuel pressure & bleed down rate.

87 Camaro Dude

I'm far from an expert so don't take this the wrong way, but if it was a fuel pressure problem wouldn't I be experiencing it regardless of what temperature my engine's at? Because it only wants to stall out on me when it's cold. And by bleed down rate, are you referring to the cylinder pressure (sorry if it's a stupid question, like I said I'm no expert)?

ex-x-fire

A cold engine uses alot more fuel then a hot one, maybe the fuel pump is weak & cant keep up. You can rent a gauge at auto zone.
Bleed down rate is the fuel pressure test when you shut off the engine, it will go up slightly then maintain psi for awhile. It should not start dropping imediately.
You also might have a cold start injector on that engine, this is an extra injector that helps cold starting. Do a search on here for more info.

firebird904

I had cold idle problems for quite a while. I cleaned up the IAC valve and the throttle body with carb cleaner and there was a lot of junk in there. I noticed a slight improvement and then I replaced my MAF sensor and since then I have not had any idle problems since. My car idles at 1500 rpm cold and around 800 once warm according to the tach.

87 Camaro Dude

Ah ok that makes sense now. Thanks for the info guys.