Hi all, my 89 740 has a wierd problem. Sometimes when I turn it on, it runs like garbage in boost. Almost like the AMM is unplugged, but only in boost. You can baby the car up to speed, but as soon as you hit boost, it stumbles right away. When I did actually unplug the AMM the car ran like crap any time above idle. When this problem is going on, if I lift off the accelerator, the needle on the boost gauge drops back down to normal and the car runs and accelerates fine until it hits boost again. If I hold the pedal in that position the car will begin to slow and I get popping from the exhaust, but the needle on the boost gage stays where it's at in the boost area. It acts alot like there's a leak in one of the intake hoses, BUT if you then turn the car completely off and restart it, the situation will either improve drastically or completely dissappear and usually remain gone until some random time in the future when you go out and start your car again. The times that it just improves but doesn't go away completely, it seems like the car can't breathe right. It will boost up to a point, it doesn't run rough, it just won't go like it should. The problem never just goes away, you have to actually turn the car completely off, and then restart it. Because of this, I'm convinced that it's an electrical issue, but I went ahead and changed all of the rubber hoses from the AMM to the throttle body, inluding the short one that connects to the turbo, I've swapped the computer, and I've unplugged the O2 sensor. At first, I thought I had found the problem. The car ran great for a couple of days, but then this morning when I came to work, it did it again. So now I don't know whats going on. I've tried searching the forum, but can't find any other posts. It doesn't matter if the engine is warm or cold. Could it be the AMM? I bought a used one and tried swapping it just to find that the one I bought was DOA, the car wouldn't run above idle. What am I missing?