1991LX5.0

ive been working on one of my friends cars for a while now and were having some weird electrical problems, usually im pretty good at figuring out electrical stuff but i have no clue whats going on here. Last week he told me he filled up at the gas station, started to drive off and everything just shut off and wouldnt start back up. So when i first got it i tried charging the battery and it would drop to about 6v within a minute, so after looking at everything i finally figured out it was the two week old optima battery, so we got a new one in the car and it holds voltage fine but i wasnt hearing the pump prime so i put 12v right to the pump and got nothing, and this was on a 4 month old pump. So after we put the new pump in and now it primes but the car wont start no matter what we try, before we had these problems it would start up right away every time no problem. I checked for spark and its good and fuel is good. does anyone have any idea what is going on?

jwog666

i know you said that the pump runs, but did you check fuel pressure? injector pulse?

mstngsule68

check for codes