5-10 Psi In Vacume When Idling (idles Really Bad)

[Kowalski]

alrighty well iv replaced just about every vacume hose except the boot, and then i replaced the one that goes from the bottom of the boot to the arm that clips onto the coolant arm and then to the ICV i have replaced every hose except those 2 and i put a vacume gauge on the brake booster hose and its only reading 10 psi max and when the car is about to die it drops down to about 5. i do have after market cams in the car but they were put back into the same spot that they were taken out from i dont believe that they would cause a 10 psi drop in presure. but when i rev the car up it gets up to 20 psi... which is the normal psi im not sure what the deal is there... so any sugestions would be apprieciated.

[Kowalski]

also my fuel milage guage doesn't work and only works at about 3000+ rev's and when its like that it shoes at maxumum consumption... so is this related to my MAF?

Here's another thing: If your engine dies while driving - watch the gauges.

It may be the relay that powers the ECU. If the tachometer drops to zero while the car is still rolling in gear, that is surely the cause.
If the tachometer keeps showing the correct value, but the econometer shows a fuel cut, the problem is in the air flow meter.
If the tachometer shows correctly, and the econometer indicates there there is still fuel consumed, the problem is the fuel pump or its relay.

quoted from http://www.esatclear.ie/~bpurcell/318isfaults.html

[Kowalski]

also when i tap on it it sounds like there is a loose spring or somthing inside of the MAF, not sure if they all do this, somone wanna tap on theirs and see? its a 91 318is. but the flap does move freely and it also springs back to the shut possition.

[Kowalski]

also i cleaned both the MAF and the ICV im wondering if it might be my crank positioning sensor thats causing the thing do die, i hear thats a common problem with these cars, so would that be worth it to replace? its got like 260 km on it, is there any way to check it to see if its functioning? would it make the engine light flash if it isn't?