9165pt0

Today i was criusing the mustang and it was running great. then all of a sudden it dies out. i have lately heard the fuel pump be louder than normal. but i thought it was bcuz the rear seats are out of the vehicle. once it died out and i tried to restart, i have noticed at key on the fuel pump continuosly primes. it doesnt stop priming at all and is extremley loud. car wont start at all.

plz help, i was thinking the fuel pump went out but upon searching some ppl say its the ecu. how can i make sure. thanks

dbows50

I am not sure of the wire colors but if you look it up one wire come from the ecu commanding the fuel pump on for a few seconds " prime" then ones it sees the car is being cranked it turns it on continuously. If you find the wire from the ecu it probably has 12 volts it may even be 5 but that will tell you when it's commanded on once that happens the constant 12v wire gets its ground and the pump turns on. I would say its a bad pump I never heard of an ecu going for that reason. If the pump was getting louder it may be because it was waring out internally and struggling. With a fuel pump running all the time would let a car start. The reason why it might not stop priming is there might be a sensor monitoring fuel pressure and it's not seeing it go up enough so it's on a constant run mode trying to meet the specified fuel pressure.

uedlose

check for spark to see if you are getting any. the pick up in the distributor may have went bad and that is why the pump is running all the time and may be why the car wont run.

9165pt0

thanks 4 info, ok guys i had a chance to check it out. the relay seems to be good, there is spark, all ground seem ok. seems like it mayb a bad computer, which sucks. are the known to die out over time? also its pita to remove, lil to no room to work, and the main harness seems to be dead stuck together with the computer. just have to keep at it i suppose, since its been in place for over 20 years. ill be swapping out the comp and give an update.

arco212

I was searching the posts I have the same problem. fuel pump runs always czr crznks but no start did a new ECM fix it?

88 orangepeel notch

As I'dwin said in the 3rd post, check for spark first. Even with the fuel pump running constantly, the car should start and run. Let us know what you find.

Good luck and welcome to the forum.

Etadrous89

You said it's getting spark, which is a pretty good indication of computers working fine, gonna guess that air filter is good (because as a joke my friends stuffed shop towels in mine and it still started), sooooo is it getting fuel???? In a 94 i got there is a little nipple on one of the fuel rail (may or may not have cover) that almost resembles a tire valve stem put a key or something small in it (watch your face) and see if it squirts fuel… it should be a lot not a couple of drops or air… If not more then likely you ran out of gas! Hope it helps!

mjr46

that has no bearing on the computer working fine......ecm doesn't produce the spark

dbows50

It's most likely the pickup in the distributor. It will cause the injectors not to fire. Plus your fuel pump is priming so you most likely have fuel. make sure your not out of gas and change the pickup and it should fire up. If not then it's the ecm but I thought it was rare for them to go bad

64bit

Every single one of you... SMH

This thread is from 2012, and the OP hasn't been active since June.