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snapontech
snapontech, Auto Mechanic
Category: Ford
Satisfied Customers: 3803
Experience:  2 Year Automotive Degree 2 years hands on technical training and 7 Years hands on learned from the best.
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1987 Ford F150: cyl engine..the fuel pumps..high pressure pump..rail

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I am working on a 1987 Ford F150 6 cyl engine. I cannot get the fuel pumps to power up. When I apply power directly to the high pressure pump on the frame rail it runs. I removed the intank fuel pump from the front fuel tank and when I bench tested it, it also works. The fuel sending unit does not work even when bench testing it. I have checked the voltage at the plugin for the high pressure pump and only get .3 volts with ignition switch on. When I check the voltage at the pluggin for the intank pump, I get 12 volts for a moment when I turn ignition switch and then reads 0 volts. There are two relays behind the air intake on the left fender. One pluggin is green and the other one is brown going into the respective relays. I believe one of them provides power to the fuel pumps. Which one is it? When I probe the plugins for each of these relays with ignition switch on and relays plugged in 3 wires on each relay measure 12 volts and 1 gives no reading. I have cleaned the 2 ground wires connecting to the main ground wire on the battery but there was next to no corrosion. Any suggestions as to why I cannot get power to the fuel pumps?
Thanks

Clayton

snapontech :

Welcome to Justanswer, My name isXXXXX am here to help.

Customer:
I am working on a 1987 Ford F150 6 cyl engine. I cannot get the fuel pumps to power up. When I apply power directly to the high pressure pump on the frame rail it runs. I removed the intank fuel pump from the front fuel tank and when I bench tested it, it also works. The fuel sending unit does not work even when bench testing it. I have checked the voltage at the plugin for the high pressure pump and only get .3 volts with ignition switch on. When I check the voltage at the pluggin for the intank pump, I get 12 volts for a moment when I turn ignition switch and then reads 0 volts. There are two relays behind the air intake on the left fender. One pluggin is green and the other one is brown going into the respective relays. I believe one of them provides power to the fuel pumps. Which one is it? When I probe the plugins for each of these relays with ignition switch on and relays plugged in 3 wires on each relay measure 12 volts and 1 gives no reading. I have cleaned the 2 ground wires connecting to the main ground wire on the battery but there was next to no corrosion. Any suggestions as to why I cannot get power to the fuel pumps? Thanks Clayton

Country: Canada
Make: Ford
Model: F150 Pickup 4x2
Year: 1987
Engine: 6 cylinder

Sent to Ford Experts Today at 8:02




snapontech :

Hello

snapontech :

Have you checked the inertia switch?

Customer:

Yes. That does not appear to be the problem

snapontech :

What is the reading on the switch with the key on?

Customer:

I'm assuming you mean the reading on the inertia switch. I did not check that but the white button on the switch was not popped up. I am away from the vehicle now so cannot check the reading

snapontech :

Even with button up doesnt help

snapontech :

They go bad all the time on this model

snapontech :

The brown wire should have 12 v then the other side should be 12v pink black

snapontech :

If not then that is the problem for sure

Customer:

I will have to check that reading and get back to you. It will take awhile as I'm away from my shop. Will get back to you in about 1/2 hour

snapontech :

Ok

Customer:

When I checked reading on brown wire it had 12 V momentarily when I turned the key on. The pink black only registered .3 V. Bypassed inertia switch and all 3 pumps now work. Problem solved. Thank you very much

snapontech :

No problem

snapontech :

Please press the green ACCEPT button in the lower right

snapontech :

feedback is appreciated!

Customer:

Why didn't I contact you 4 hours ago? Would have saved me a lot of time

snapontech :

Yep now you know my name is XXXXX XXXXX I have a link http://www.justanswer.com/car/expert-automotivedoctor/

snapontech :

If you need anything in the future

Customer:

Thanks

snapontech :

Good feedback is greatly appreciated as well, let me know if you need anything else. I am always available so anytime

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