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Eric Gardner
Eric Gardner, ASE Certified Technician
Category: Ford
Satisfied Customers: 233
Experience:  ASE Certified Automotive Technician with a Bachelor’s Degree in Automotive Technology
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Ron I have a 1991 ford f150 4x4 5.8l my fuel pump went out

Customer Question

Hi Ron I have a 1991 ford f150 4x4 5.8l my fuel pump went out and I replaced it, I now have 45 psi at the rail and good spark. I have power to the injectors but the truck will not fire . If I spray down the throttle body it fires right up until I stop spraying. any ideas thanks ken
JA: Have you ever replaced the fuel pump, or is this the original?
Customer: just did
JA: What is the model of your '91 Ford?
Customer: f150
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes new pump and filter psi at the rail is 45
JA: Anything else you think the mechanic should know?
Customer: I have power to the injectors only runs if I spray down the throttle body
Submitted: 1 year ago.
Category: Ford
Customer: replied 1 year ago.
I also replaced the pip sensor and pulled to codes 1 was tps and the other was the map sensor?
Expert:  Eric Gardner replied 1 year ago.


Have all the fuses and relays been checked for operation? Also has the fuel inertia switch been tripped and if so have you been able to reset it properly?

Customer: replied 1 year ago.
all fuses checked and good did not check the switch not sure were it is located
as are all relays eec and fuel pump working properly
Expert:  Eric Gardner replied 1 year ago.

The inertia switch is located under the drivers side of the dash. It will have a red button on it that will need to be pressed down. After doing so try starting the vehicle again.

Open the link below for a picture.

Customer: replied 1 year ago.
ok be right back
Customer: replied 1 year ago.
still no start
Expert:  Eric Gardner replied 1 year ago.

Okay so we ruled out the fuel issue completely now.

The map is the next item we need to take care of. If the MAP has failed the engine will definitely not start. Are all the wires going to the MAP in decent shape and the vacuum line coming off of the MAP is intact and the connections are tight.

If this all looks good, I want you to press the throttle to the floor then try and start the engine while holding down the throttle the whole time.

Expert:  Eric Gardner replied 1 year ago.

When you say the PIP has been replaced, do you mean TFI? Not sure what PIP stands for?

Customer: replied 1 year ago.
vaccum looks good no visable wiring problems held gas to the floor no difference just cranks does not try to start
Customer: replied 1 year ago.
replaced the whole dist. wires in it were very dry and flaky was told the sensor in the dist. was called a pip sensor
Customer: replied 1 year ago.
just change map it runs thank you