1990 Jeep Laredo fuel pump

Last year the car would sometimes crank and run and other times would crank and stop as soon as the key switch returned to the run position from the start position. Finally it stopped cranking at all. Did much checking of electrical, replacing the switch on the lower steering column, checked relays and interchanged them. Checked the connector at the fuel pump but could not get a reading. Finally ran a jumper wire to the fuel pump but the pump wouldn't run. Replaced the pump and car started right up and ran great. Now the problem is beginning again. Sometimes it will crank right away and run fine. Other times it will crank and cut off as soon as switch returns to run, but after 10 to 15 tries it will finally continue to run. Any help would be greatly appreciated.