One of the most common problems with the 88-91 4-cylinder Troopers is stalling/no-start due to the fuel pump control circuit and associated wiring. It may look like the pump, but it might also be one of the electrical connectors or the alternator (there is a signal from the alt that closes a relay which runs the pump; failing alt = no signal = no fuel).

I've spent lots of time on this problem myself and ended up rewiring the system, but there are many posts on the forum dedicated to diagnosing and repairing it properly.

That is the reason he was asking you whether you were sure it was the pump itself.