dzzy

I have a 1987 ford f150 efi 5.0 with a c6 transmission and it wont start. its not get fuel to the rails on its own unless you jump it on the relay. all reference voltage is fulltime battery voltage and it should be no more than 5 volts. Changed computer and still having the same problem. Can anyone help me with this.

94f150-5.0

Check your fuel tank selector switch

Chris_1

iTrader: (1)

Could be a bad connection under the relay as well

dzzy

Ok i will check out both of those and update tomorrow. Thanks for the suggestions.

dzzy

**** UPDATE****

Checked the check the connections under the relay and the fuel tank selector switch both of those things are good the problem I see now as well is that the fuel rails when turning the motor over the fuel rails don't fire When turning the engine over. Its like the computer thinks its in wide open throttle. I dont know if it is a ground problem or what.

Chris_1

iTrader: (1)

Check the TPS. - On or about feb 22 "checking the TPS"

dzzy

****UPDATE****
The TPS is good. it seems that all reference voltage is reading battery voltage at all the sensors. Checked all the sensors and they are good. This one is got me scratching my head. I do appreciate all the help You are giving me.

alnen

Have you checked for codes?

fltdriver

So this means you have .9-.97v at closed throttle, 5v at WOT, smooth increase when opening it up?

x2 on pulling codes just for reference.

If you happen to have an extra FP Relay you could try swapping it out to see if it's the relay that's stuck, or you can test it out of the truck. I know how to do the bosch style but couldn't help you with this one.

Ensure that you are getting signal at the relay, from ignition, when key is turned.

94f150-5.0

Also clean your engine to frame ground