<hr style="color:#F66516; background-color:#F66516" size="1"> Hey guys I have a 2000 Impala 3.4l, it has a rough idle and hard starts sometimes. Probably the fuel pressure regulator, But what does this vacuum port go to on the manifold, I think something fell off, I cant find a vacuum line anywhere that would plug into it. and if I plug the hole with my finger it will cause the car to die.

Notice RED arrow in the pic

THANKS ALOT!

 

please alittle help guys, ideas?

 

Welcome to the forum. There should be an emission and vacuum label under the hood. It looks to me like an accessory port on the intake manifold. If yours has the Secondary Air Injection (AIR) system. the port is probably for that. It sounds like it's just a source of an air leak in your case. Maybe the IAC valve is inoperative and the air entering through that port is the only thing that keeps the engine idling.

 

I have the same car, 2000 with the 3.4. It has the same port on the intake but it has a little rubber cap on it, sealing it off completely. Of course it runs fine that way. Which leads me to believe, as EinST meantioned, its an accessory port not meant to be open without being connected to whatever its meant for.

 

Thanks alot guys! i think your right, Ill try cleaning sensors and such and ill plug off that vacuum. Thanks alot

 

It should have a rubber cap