1991 F150 (6 Cylider) 2 tanks, 150,000 miles, Plenty of spark.
Problem Occours on either tank.
here's the deal;
When working properly I turn Key to start position and can hear the fuel pump kick on for it proper 5 seconds or so... Engine starts fine.

When NOT working properly, I turn Key to start position and can hear the fuel pump kick on and stays on sometime long enough to cause the relay to "click click click" Of course it will not start when it's doing this. Often I can wait 10-20 seconds and fuel pump stops, then she starts normally, lately though it goes and goes untill it starts irritating the relay,

I took it in to one guy, and of course she starrted like 30 times in a row.
Called another guy and both said that untill it's broke they can't fix it.

Took it into a 3rd place, more of an electical diagnostic place, the problem finally surfaced for them, but they were unable to pinpoint the issue. But they agree that it seems electrical in nature (not fuel line/pump). Anyway they replaced some worn grounding wires and said "try it out! ($158.00) but we are not sure". He's thinking maybe the computer is failing, but hasn't failed yet, or something is causing the computer to miss a signal Of course thats not a cheap enough repair to just "try it".

This is driving me nuts , I work 2 jobs x 12 hours a day and don't have the time to sit around hoping it starts. if anyone has ANY guess's i'd love to hear them. The Last guy would've checked obvious electrical's and I don't have the skill set to start measuring ohms and all that.

i did replace the $10 relay (did'nt make any diff)

What would be the most likely part that need replaced??

thanks in advance!

 

computer USUALLY does that when going out. try a junkyard computer at least if it gets better then u could either get a new computer or just run the yard one. i was quoted 45.00 for a ecm here in ohiio

 

classic computer failing sign.

start pricing them.

 

Where is the Computer? and how do I identify which one I need?
Thanls again for your speedy responses!

 

oh and is this a job a totaly retarded amature (like myself) can do? Or will it require some specialized equipment and/or technical Knowledge?

 

it is below and to the outside of the master cylinder.

not hard to get out.

you have a manual right? it shows how to do it.

get the numbers of of it, the old one.

disconnect the battery before you start working.

 

Thanks again!
Manual? What is theeese manual, we don neeed no stinkin manual.

 

that is the location on a 92 and up.

the 91 may be different, let me see if i can find if it is different.

in the chiltons it looks like it is in the same area but it may be removed from the inside cab instead of the engine compartment.

 

ah, actually you do.

 

It should be a requirement that anyone who posts gets a manual first. From back when I was in high school, when you bought a truck, the first thing you did was go out and buy the 900 page Chilton's for all trucks (Dodge, Chevy, Ford, etc.). Now-a-days, I guess it is easier to ask someone else.

 

I have a manual, but it's not Chiltons and as such seems about worthless, to me anyway. It is written with the expectaion of a level of mechanical experience that I do not possess. The Manuals are great if you know what you are doing, but rarely help a novice diagnose a problem. Not sure if Chiltons is the same, but more importantly, I'm not sure that the Truck is worth the $20.00 the book would cost. Get a "Gray's Anaotomy Book" and you still will know zilch about medical practice.

 

Thanks for all your Help Quicklook, I really appreciate the time you took. The couple of wires that the electrical Diagnostic place replaced (on a hunch) are working so far, he also added a ground at the battery, that he wasn't happy with , he said it was throwing off a little voltage. I've started her like 25 times since I picked it up , so far so good. If it craps out again I'll probrobly see if I can locate and replace the Computer.
THANKS Again (for you paitence as well)
Red WolfHopw

 

First do not replace computer.I had same problem with 92 and I had to
replace fuel filter.Truck had 80,000 miles with factory filter on it.I would
try this first before going any where ,its cheap to replace and easy.Go to any parts store and buy filter and special tool to remove filter.After filter is removed
place a canister of some sort on end of line coming from fuel tank and have someone for a couple of seconds turn key to on position to purge line from tank to canister.Once fuel is running clean replace filter.

 

Looks like it probrobly is the Computer, it's acting up again, same old same old, (particualrlly when its wet out. I'll replace the Computer when I get some cash and repost. Thanks again.

 

post if you have any problems.