Just for kicks I disconnected the vac line that is attached to the intake, the one that has a "T" and goes to the FPR and the pressure sensor setup. I expected an immediate CEL for the MAP. Didn't happen, so I went for a short drive. I expected to see a worse running engine. After all the FPR wasn't working and the MAP wasn't working, so something should go wrong.
No worse running engine. Hm? In fact the idle may have been a bit less lumpy but I attributed that to the increased RPM's because the intake had un-metered air entering it.
Came home stopped the car, hooked up my code reader, started the car and there was a CEL. Yep it was the MAP.
So I hooked pulled the vac line off the FPR and expected to see some kind of difference but no, not one bit of difference. I pulled a vac on the FPR and it held.
It just made me go hm??????
Originally Posted by Zues Marine
there should be a diagram of vacuum layouts in a sticker on the underside of your hood, over the fuse box..
should help you figure things out a bit better