87 gt cranks got spark got fuel stays started when i hold key turned help asap

[davidohio]

i got an 87 all stock 5.0 i got spark and fuel pres car ran fine for over 1 month then i ran into this problem again it had a aftermarket alarm in it i ripped it all out then the car would stay started only if i holded the key to the on pos but the starter would grind i started screwing around under the coluem area with a fwe wires and then it started normal so a month later i changed the battrey other day got on the high pow dead same problem soon had i chnaged the battrey before that car ran awsome i figured the coluem wires was screwed up again so i went today brouth a whole colum installed it and turns out it anit that now iam lost again i got spark and fuel so its not that the car ran great fwe days ago

 

[5.0ina66]

Hmm...almost seems like the fuel pump isn't getting switched on. I'm not 100% sure if a 5.0 is setup like this, but most cars will run the pump when you twist the key to "crank" and then they look for signal from the distributor before they go ahead and tell the pump to keep running.

If that is how it works, it could be the wiring, the TFI module, distributor itself, or maybe the ECM. Or it could be something else.

Maybe a bad crash shutoff switch?

 

[tmoss]

grammar - learn how to use it and spell check.............. you might get more help.

 

[kendoo130]

It's probably your ignition switch.

 

[TenorPlayinGuy]

It's probably your ignition switch.

+1

 

[clement]

if you mean it only runs when cranking, but wont stay running after you let off the starter....

you might check the main pcm ground to make sure it didnt come loose. check it over by the coil where its shrouded in a plastic casing. it can come loose there and not look it, and it will give the same symptom you are describing.

 

[James_G]

ignition switch i had to replace mine for the same reason. Real easy to change jus tmake sure you get a t27 tamper proof torx bit before you take it apart.

 

[JB_90LX50]

It's probably your ignition switch.

I have to agree, I havent had that problem in my mustang yet, but had the exact same problem with my 1985 F-150.