Did you get the BCA or BCS? The BCS (the electrical one) cannot dump boost if it'* not hooked up, like your current setup. Unless you plan on hooking it up, it'* a waste to get a new one.

That said, the BCS is there for a good purpose. If the PCM sees something wrong, it can use the BCS to dump boost in an attempt to protect the engine.

I ordered the non-electrical one. I went in and the parts guy showed me a pic of it. It sure looked to be pointing to the right one. It'* the one with the little arm to move the shutter inside the */C

My '89 ECM has no provisions to hook up the electrical one.

You got the BCA. Good. (boost control ACTUATOR).

Thank you Willren for explaining exactly what that meant. I didn't know the term before this situation. It was a lot cheaper than I thought it would be

Hmmm...I went back to the dealer and they ordered me the "BCS", which didn't do me any good. After about half an hour of searching the catalog, we found the "BCA" I need, at over $300 . Noooo thanks.

Do you guys think it'* my problem? I looked up the mod for it, which involves loosening the two bolts and cranking the one side of it upwards. I suppose this mod is to make it more responsive, but didn't help me in my case. I posted about an actuator in the wanted board, and sent a PM to a gentleman with one.

You guys think it'* what I need? I tried a couple things, like replacing the stock vacuum lines (which are of small diameter to me) with larger ones, and replacing the "BCS" with a vacuum line, but nothing did any difference so I put it back to the way it was. I'm thinking a salvage yard wouldn't want to sell me one since they like selling complete motors.

Are there are any things I should check before going ahead and replacing the "bypass control actuator"? (I think that'* what it is, if not boost control actuator, ehh, whatever it is...). What'* inside of it?

Thank you gentleman, and for putting up with my lack of intelligence with these units.

Adjusting it won't do any good if it'* not working.

Remove the actuator from the supercharger entirely, and plug all the vacuum lines. Force the bypass actuator valve on the supercharger fully clockwise as you face the engine, so the arm comes to rest on the base of the supercharger near the #5 fuel injector. Tape it down with something to hold it in that position. You should have full boost.

Now reinstall the byass actuator and vacuum lines. Block the front tires. Get a TRUSTED friend to get in the car, start it, and put it in gear with the Ebrake on. Have him rev the car to 3500 rpm'* in DRIVE with the FOOT on the brake, and watch the Actuator from the FENDER side of the car to see if it actuates fully to the same position you taped it to in the step above. Did it? If not, replace it. A wrecker is cheaper, and so is www.gmpartsdirect.com

I don't know who quote you 300 bones, but they're insane.

My bad, I had to re-read the post to get it in my head. Man o man, I need some sleep

I'll let you guys know how it goes.

You need the valve fully counter-clockwise to be fully closed (full boost)