sorry for the short novel: drivin down the freeway about 5 miles from home heading out of town then it started to chugg for a few seconds, like i was bouncing my foot off the gas pedal , stopped chugging and drove fine. on return trip same thing exept a little worse almost lost it completely, came back, made it home.few days later decided to take it to the store died 3 houses away, got it started went to store anyway seemed ok, couple days later made it a block and a half got it going again made back to driveway parked it minute later, died, started back up ran fine for 45 mins idling, sat under the hood with i stick poking plug wires,coil wires any wires i could see, could not get it to die. tried it yesterday wouldn't start, put a spark tester on coil damn thing fired and ran. took off tester started again died now it spits and sputters and won't start. at a loss. the fuel pump runs at a high pitch for 2 secs and then a low pitch for about 20secs. my BIL is a mech, and says thats wayyy too long should only have the fey up prime for a couple secs and be done. i do not have a way to test the fuel pressure unless theres a easy way without taking too much apart. had the wife turn it over so i could look and can see fuel pulse into the barrels. any help, thanks in advance.

specs: 5.7 tbi
new cap and rotor newer plugs/wires
90 gmc dually frankinstein

 

tap the A&B holes together and see if any code comes out.

I dont know, maybe clogged fuel filter or fuel pick up in the tank?

 

A fuel pump "could" provide fuel,but not enough pressure to start.You can rent for free a as a loaner fuel pressure gauge from your local auto parts store.You give them the value of the gauge as a deposit which they return to you once you bring it back.