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Sep 20, 2013 | 09:13 PM

jcurti

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Joined: Aug 2013

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Please help

I need some help. My grandparents have a 1987 f-150 with a 5.0 liter engine. The truck wont start. I first checked for spark and got shocked so I figure that is good. I then checked for fuel pressure with my f/p gauge, none. I then checked to see if there was power to the fuel pump, none. My next step was to find and check the f/p relay, found it located behind the air cleaner with another relay. One relay clicks when the ignition is turned on but the other one did not. So I start testing the one that did not click to ensure that I have power to it. Three out of the four posts have power. I then jumped power from a hot post to the post that did not have any power, I got fuel pressure. I then tried to start the truck, did not start. I replaced the relay thinking that it might need to be hooked up but I still did not get fuel pressure. I only get fuel pressure when I use a jumper but the truck will not start. Is this an ECM problem or is it something else. Any help is appreciated. thank you

Sep 20, 2013 | 09:28 PM

subford

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Joined: Aug 2005

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From: Easton,Ks

Yes it sounds like you may have a computer problem.
You can ground pin #6 at the self-test plug and if the fuel pumps run then you more than likely have a bad computer if you power on the computer power pins and good ground on the ground pins.

You might also check the the small black wire with a green strips has a good ground at the NEG post of the battery. Without this ground nothing will happen.