Originally Posted by captainmiller
Ok, all other problems solved except the low boost. Now, to go over what has been mentioned...
Vaccuum lines - mechanic said he repaired any leaks he found.
MAP Sensor - Causes a bad reading in the gauge, but would this not set off a code?
BCS - He said it "checked out" fine on the reading, however does anyone think replacing it would make a difference even if the old one is supposed to be ok?
Loss of rotor coating - Well, I guess I'm just screwed for that one..
Any */C geek help is much appreciated. This isn't too urgent since the car is completely driveable and the roads are messy...but it will be needed soon.
Check all vac fittings and SC gasket with intake cleaner at idle. If the idle changes, there'* a leak.
Ignore the MAP sensor for now, we'll come back to it if necessary.
SCANTOOL checks of the BCS are subjective at best, and the BCA itself cannot be checked with a scantool. Try this:
See the little vacuum line running from the BCS to the BCA? Pre-formed at about a 60 degree angle? Disconnect it from the ACTUATOR, and plug the end with something, while leaving it attached to the BCS. This prevents the BCS from controlling the actuator'* movement (in effect, possibly preventing the BCS from limiting your boost). Did your boost come back? If so, replace the BCS.
This next part is tricky. With that disconnected, get someone you TRUST in the car. Block all 4 wheels and set the parking brake. Have you trusted helper REV to at least 4k rpms in DRIVE with the other foot on the brake (helper must actually have 2 feet). You watch the actuator from the SIDE of the car to see if you get full travel of motion or not.
Here'* the deal why:
By default, you have no boost. It'* bypassed. When you roll on the throttle in a drive gear (BCS prevents boost in a non-drive gear selection on the shifter), the BCS moves the BCA in the direction of non-bypass, slowly bringing on the boost based on manifold vacuum.
A full function test of the BCA could also be performed by connecting a vacuum hose from the BCA all the way to where the BCS is NORMALLY hooked up. Totally removing it from the equation. I'd have to go out and look at the plumbing to be sure on this one. And it'* cold outside.
I'll have a better description of the controls for you shortly. Work in progress (your timing is impeccable).