helpinafriend

91 4.9ltr cranks but won't start unless starter fluid sprayed into system. Apparently hasn't been operating correctly for a short(1-2 months)while. Friends truck he thought it was the fuel pump, i took his word and replaced it for him. Still not working.

replaced:
front fuel pump
fuel filter
fuel regulator
MAP sensor
Fuel pump relay
TPS

Removed both fuel lines from fuel rail and fuel pumps out full stream from front or rear pump. If I spray starter fluid in, let it sit for 5 seconds then it will start and run for 2 minutes at half pedal. I can let on and off the pedal and it will run accordingly but if I press to hard it sputters then stops. Then no restart. Any thoughts or suggestions would help. I'm used to Pontiac, Chevy, Volvo, and Toyota can't think that Ford is that much different. I just need to learn. Thanks

PS: The check engine light is on but for the life of me I can't seem to read any code use the CEL according to a post listed in the how to section and the battery has been disconnected at least 3 times with no reset