Hi folks!!!! I'm new to the forum..just signed up today and was hoping I could get some help with a problem. Just aquired a 1990 F250 4x4 a couple days ago that has been sitting a couple years. It cranks over great but won't start. When I spray starting fluid into the air box it fires up for a few seconds so I think I have a fuel delivery problem. I'm also thinking I should be hearing the electric fuel pump kick in when I first turn the key ..but I don't hear a thing. I'm looking for the fuel pump relay but don't see it. I'm told that it is on the driver side wheel well but I'm not seeing it. I was hoping someone could give me a little more help in narrowing down the exact location. Any help would be greatly appreciated!!! Also, someone told me that this year of truck might have a fuel shut-off switch located somewhere. Is this correct?? If so, where might that be located. Thanks in advance for any help!!!!

 

fuel pump relay, and eec relay right behind the air cleaner box. switch is either right behind the brake pedel, or in pass kick panel, depends on the year. check all your grounds first, most times that winds up being the problem on trucks that have sat for a while

 

Yeah, right behind the airbox, mounted on top of the wheel well, you should see a little black box just big enough for two relays. Of course, when I got to mine, the fuel pump relay wasn't in the box, it was just laying in a pile of wire harnesses back a little closer to the brake booster.

 

Photo of the Relays:


Inertia Switch (fuel shut off switch):


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Thank you folks!!! I see what I am looking for now. Heading out to the garage right now!!!

Brett

 

The trick is going to be getting those relays out of that plastic cover they reside in. I ended up breaking all the posts the relays snap into. That is probably the same thig that happend to Milehawk's truck that's why the relay was sitting in a pile of wires. I ended up tie strapping all three relays together and securing them to the mount that previously held the relay cover. Does anyone know if those covers are still available?

 

I could never find any, just wrapped zip ties through and held them in like that, I found if you leave them bounce around on the inner fender, they have a very short life span

 

O.K..........I replaced the fuel pump relay and I found and checked the fuel inertia switch. I also cleaned the body ground connections under the hood. Still I get no fuel pump sounds and it appears that I am getting no fuel. Cranks over great...just no start. Anybody got any suggestions where to look next?

Thanks,
Brett

 

When you had the relay out did you confirm that one of the posts was hot with the key in the run position? Second thought, do you have dual tanks? I'm not an expert on the fuel system and mayby some will correct me on this but if the pump is located in the tank then switching tanks and still having no fuel would eliminate ate least that the pump was at fault.

 

No, I didn't test the posts but I will now. And yes, I have the dual tanks but I don't hear any pumps running when I turn on the key. The back tank IS empty....I'll put some gas in and try that. Any ideas are welcome. Thanks!!

 

Ground pin #6 of the EEC test connector.
Turn on the key.
Do you now hear the selected fuel pump run?



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pump comes on for 3 seconds when 1 st turn on key, then goes back off. it does not come back on until it gets a signal from the distributer that the engine is running. it don't care if there is fuel or not. 1.have someone stick ear by open cap on fill, turn on key, see if pump runs.2. open the air cleaner tubes by the throttle body, and spray some carb cleaner in the throttle body while someone is cranking the starter. if it starts, it's fuel pump. if not it's eec, or spark.check the ground up on the core support behind the driver side headlight, that is where my ground was bad, fixed it, and fuel pump fired right up

 

I am going to change my fuel injectors. Where is the inertia switch as I
need to purge the fuel out of the feul rail lines before I start this project?Or is there some other way I can purge the lines.I Have 1 1990 Ford F250 7.3 Diesel.No power stroke.
Challe

 

You do not have one. You fuel pump is mounted on the engine and does not use electricty.

 

Thanks a lot for you for the info. Will I have a problem changing the fuel injectors without purging the fuel rails?
Challe