Slowass2dr

alright i have 88 turbo wagon with a 1.5 single, anyways wen i got it the rpms would go up and down like if i had a vaccum leak, so i was just taking a look at my motor and i placed my hand in front of my blow off valve and it was sucking air in, and wen i coverd the bov the engine would then idle perfect, i was like wtf, is as if the bov is openned all the time. the bov is a plastic bosch one it pretty crappy but am not sure if its the bov....what do u guys think?? btw yes there is a vaccum line that goes from the intake manifold to the bov. thanks guys

MAJORAHOLE

i don't think it should be sucking throug there. i have a bosch, but i've never thought to see if it is sucking in.
btw i don't think that IC is doin much.

Hitchhikkr

The early bosch bov's are notorious for leaking, if you look at the valve from the underside and all you see inside is the rubber seal and no metal parts, then chuck it in the trash.

whiterice

the factory bypass valve are designed to be open slightly at idle.
there is a website that shows you how to add a large one way valve to the bosch ones to fix the problem.

whiterice

Here is an example using a Bosch BOV. This fix applies to all BOVs that may be slightly open during idle.
http://www.geocities.com/kilruf/bov.html

MAJORAHOLE

good info.
that might be why my idle jumps after my car warms up.