My tensioner arm wore out Friday and fell off. I replaced it but now the car will start fine and idle for about a minute then stall. If I hit the accelerator it will also stall. It acts as if it getting too much gas the moment the acceleraor is depressed. I'm thinking one of the sensors is bad but which one? After it has ran for the minute and stalls it will turn over but dies immediatly and won't start agian until it has sat for awhile
When it won't start, test for spark. I suspect your crank sensor or connecting wire may be the problem....
I don't know if this is the answer, but I've learned a lot recently that the W body GM cars around this time had a common problem with the wire from the crankshaft position sensor to where it plugs into the harness, going to the control module (control module sits behind the big black box where all of your spark plug wires end at). It is possible the insulation wore off (like mine: http://groups.google.com/group/alt.autos.gm/browse_thread/thread/8d00f130c556e6ba ).
When you're hitting the gas, you're making the engine torque (move a little). That might be enough to make that wire hit the metal of the engine or transmission pan. My understanding that this wire is an extremely common problem, and wasn't just a coincidence on mine. Of course there can be many other things causing this problem, but I just wanted to point this problem out so that you can have many opinions/options to consider. If they worked on your tensioner arm from the bottom of the car, then it is possible they hit some wires and repositioned them closer to metal of the car. There is only like 1/4 inch of play with metal for that crankshaft position sensor wire. So if the insulation, or the plastic wire harness connector is wore off/burned by heat and touches metal occassionaly, from the vibration of the engine, then it will sure enough cut off. Mine would more so do it at idle, but sometimes buck when at other ranges. If you read my post at the other link, then maybe you can try to find those wires that lead to the connectors on the control module (black box with the spark plugs wires) and grab them and move them, see if it changes the frequency of the problems. Moving them from the top of the car may not make much difference. I found that moving them from the bottom (laying on ground by passenger front tire) made more of a difference.