91 tsi rough idle

[jcorn517]

Hey guys I'm totally stumped I got a 91 tsi awd completely stock it has a horribly rough idle all the time I've replaced plugs wires checked for boost leaks and can't find anything wrong except for the blow off valve (1g) when I take the recirc tube off there is a solid stream of air coming out...could that be my problem? Need a new bov? Any ideas would help please thanks

 

[93Lzr]

Air coming out of the blowoff valve? Mine has a little come out but when the recirc tube is on it idles fine. Have you looked at fuel pressure or timing?

 

[brownie956]

That may be your culprit, there shouldn't be air coming out of your BOV at idle. I'd check that there are no more leaks in the intake system, all your vacuum hoses are in good condition, and you don't have any major wires unplugged (like to the CD deck) as well. Good luck.

 

[JustinP10]

Shouldn't that be under vacuum at idle? That'd be sucking in un-metered air? Running lean at idle will cause it to idle rough.

What happens when you plug the BOV opening with your hand, does the idle smooth out?

 

[pauleyman]

It doesnt matter if the bov even works if the recirc tube is in place. It will not affect idle. Yes a bov should blow air at idle if you remove the recirc tube. Thats how a bov works, it opens under vacuum signal from the rubber line. Did you check for leaks? What is the current rpm at idle? Did you check base ignition timing? Did you check mechanical timing? Does the car have balance shafts?

 

[jcorn517]

could it be my pcv valve? Timing is good I've did a blt it holds 22 psi strong no leaks New plugs.last night New wires last night and still idling the same this morning

 

[schalk35]

Check your maf plug?

 

[jcorn517]

Weird thing is I started it this morning still had a rough idle drove down the highway this morning to work got off the highway the car idled normal I'm so stumped on this situation

 

[ChiTownHussla]

loose connection or eCT possibly?

 

[jcorn517]

What is a ect?