Ford Repair Questions? Ask a Mechanic for Answers ASAP
What engine does the 1999 F150 have?
Have you checked for power at the inertia switch under the passenger kick panel when you turn the key to on. You should have power on the DARK GREEN/YELLOW striped wire. Then check for power on the PINK/BLACK striped wire at the same switch turning the key to on.
You will only have power there for the first 3 to 5 seconds to prime the fuel system or constant power while cranking the engine.
All you need is a meter that can measure DC voltage. Then, with the switch still plugged in, take the meter lead and try to push the point into the back side of the connector and touch the metal wire pin. Place the other meter lead on a good clean ground.
As for time, just reply back when you can on this post. I will be on line till 11 tonight, I am on the East Coast. Then tomorrow I have to work at my dealership, but I'll be home after 6:30 PM. I'll get an email when you reply back and I'll get back to you as soon as I can.
I'm on here to help. Take your time and ask any questions necessary.
Do they stay on when you are cranking the engine over?
There will be power for 3 to 5 seconds just turning the key on, constant while cranking.
Take your time.
Ok. Remove the fuel pump relay and look on the bottom of it where the pins are at and see if it has numbers by the pins like 87 86 85 87A and 30.
Ok. Leave the relay out and use a piece of wire or a paper clip and jump pins 30 and 87 and see if the engine runs.
Ok. Remove the jumper and check for power on pin 30 of the relay when you turn the key to on. See if you have constant power on brief power like at the inertia switch.
Check the power on pin 86 and then check for a ground on pin 85 when turning the key to on.
Place one meter lead on the positive battery post and the other lead on the pin 85.
Ok. The PCM (Engine Computer) supplies the ground to the fuel pump relay.
Have you been able to get any trouble codes from the PCM?
Some auto parts stores loan or rent them out.
That is for the transmission range sensor. That sensor tells the PCM what gear the transmission is shifted into.
Clear the code. Then move the shifter through all the gears while you try to start the truck and see if the code returns.
keep me informed.
Does the check engine light come on when the key is turned on and go out when the engine is cranking over?
Ok. We need to check continuity between pin 85 and the PCM connector pin #80. Below is a pin out for the PCM connector. Do it with the battery disconnected and the PCM disconnected.
Pin 85 is the ground in the fuel pump relay and pin #80 is in the PCM. The PCM is located on the passenger side of the firewall behind the right front fender well under the hood. It has a 10 mm bolt in the center of the connector.
Sorry, had to walk my dogs.
The wiring connector that pulls away from the PCM.
Ok. One last test. Put everything back together and use a section of wire and connect one end to a good clean ground and take the other end and attach it to pin 85 in the fuel pump relay and reinstall the relay. Then see if the engine starts. You may have to cycle the key a couple of times to get fuel back to the engine.
Check and see if you have constant power at the inertia switch while cranking with that wire still in place.
I'll be at work at my dealership tomorrow, but I'll be home after 6:30 PM tomorrow. I am on the East Coast.
No, just reply back on this posting. We can talk back and forth till we fix your problem or you are satisfied.
Check for fuel pressure at the test port on the fuel injector rail on the passenger side of the intake halfway back. You should get a large spray of fuel if you do not have a fuel pressure tester gauge.
Yes, turn the key on when you check the fuel pressure.
The fuel pump you replaced, was it just the electrical pump motor or was it the complete fuel pump assembly?
You could have a bad pump. I do not recommend replacing just the pump motor. You should replace the complete assembly. Airtex makes a replacement pump that any auto parts store should carry.
Check and make sure you are getting power to the fuel pump first. You will have to go to the connector for the fuel pump and check or pressure there.
One line is pressure and the other line is the return line to the fuel tank.
You can check the fuel pressure at the fuel filter or follow the line from the fuel filter back to the pump.
To check for power at the pump, check for power on the PINK/BLACK striped wire.
Check continuity between the inertia switch Pink wire and the fuel pump connector pink wire.
Are you still getting power at the inertia switch?
If you are getting power to the pump, and no fuel pressure, then the pump is the problem.
I am on in the evening after 6:30 PM after I get home from work.
Your welcome. Keep me informed.