I bet it is the diaphragm(sp?) that keeps the idle up on 74's for a few seconds when braking. It is on the back left side of the carb, and hooks directly via vacuum line into the emissions VSV on the LH fender. My vacuum line got disconnected and it stalled a few times. figured out the hose was off and it worked great again, but if the diaphragm in the housing is bad, you might be screwed.