Hi, new to the forum. For that I apologize.

A couple of months ago I bought my 92 SSEI with 80000km on it (oh, that'* like 50 000 miles)

All of a sudden I can't get my supercharger to work. With a negative boost kpa there is no way to know there is anything wrong with the car. As soon as there is positive pressure the engine rattles (badly) and there is no performance increase other than from the increased RPMs. So with the car running great at a neg pressure this can't be the coupler can it?

Thanks in advance.

Rob

The coupler would rattle at idle.

I don't suppose the check engine light is on?

We don't know if it'* the SC or not, so I'm gonna move this to 92-99.

Sounds like an intake gasket under the SC. I've had this go a few times myself. It'* probably a $200-$300 job at a shop or you could probably do the work yourself in less than a day if you are descent with tools.

Explination: Once the boost gets up to 0 on the gauge, it actually with force the boost out thru the leaks vs keeping in the engine. this will cause stumbling and very poor performance. With the vacume at idle and lower rpm'* this leak is not very notiecable.

That would be my educated guess from what info you have posted. Try reving teh engine in park (not higher than 3k rpm though) and see if you can hear any whistleing from the top of the engine. If you do, it could very well be the issue.

Take the belt off and spin the SC by hand back and forth. Any slop? Vacuum lines to the BCS and BCA attached? What does your harmonic balancer look like?

In park i can rev the engine all i want and it sounds normal. But the supercharger wont boost in park. -1 kpa boost; the car runs great. 0 and up; the car shakes like a polaroid picture.

Just a thought, check out the tranny mount on the front right corner (looking at it) at the bottom. Have the car in park and not running and push backwards. Does the mount move?

Right, in park it won't boost since the bypass will dump it. But a quick rev will allow boost to build for a second before it all gets dumped. Do you hear any whistleing from the car while driving it? Are you sure it has nothing to do with what RPM you are at?

I am thinking like the other Bill...check BCS Boost Control Soleniod.

OK ya there is no slop turning the SC by hand (I was kinda hoping that was it) Harmonic balancer looks good. I'm 100% sure it has nothing to do with the RPMs. But I’m off to go check the vac lines and the BCS. Um...ha... what is the BCA and how do I check it? Feelin silly.

Thanks everyone for the responses, this forum is awesome.

BCA is the actuator that actually controls the wastegate valve. It'* the black cylinder with vacuum lines to the top and bottom, and a rod that moves in and out the bottom.