Start problems/1986 F250
Thread Starter
|
New User
Joined: Aug 2013
Posts: 13
Likes: 0
From: Fort Jones, Ca
Start problems/1986 F250
This truck sat for maybe two years without starting at a friends house. Had to put new belts on it, dogs chewed them up. Then tried starting and no go. It has fresh fuel in the tank and spark. I sprayed fuel in the EFI throat while cranking and it runs. It just ain't getting fuel up to it. Any ideas would be appreciated.
Not sure on the motor, but it is a small block, so 302 or 351 I'm guessing.
Not sure on the motor, but it is a small block, so 302 or 351 I'm guessing.
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
Listen for the fuel pump to cycle briefly when you turn the key to on. If you don't hear it, the impact switch could be tripped. I think on your truck it is located at the bottom of the steering column.
Elder User
Joined: Jan 2012
Posts: 698
Likes: 0
From: Norman, Ar
The engine will be a 302..
The 351's weren't EFI until later on...
Trav.
Also, if your pump does run, the fuel filter may be plugged...
The filter is on the left(drivers side) frame rail ahead of your fuel tank...
It should be theaded on one end and a clip on the other...most filters come with the new connector..
I think I'm right on this
The 351's weren't EFI until later on...
Trav.Also, if your pump does run, the fuel filter may be plugged...
The filter is on the left(drivers side) frame rail ahead of your fuel tank...
It should be theaded on one end and a clip on the other...most filters come with the new connector..
I think I'm right on this
Thread Starter
|
New User
Joined: Aug 2013
Posts: 13
Likes: 0
From: Fort Jones, Ca
OK. I went and pushed the reset and nothing happened. No sound from the pump. I did crawl under there and seen the filter with the pump just behind it. You'd think that the pump would be fused, but couldn't find it. Guess I should've checked to see if it was getting power to it?????
If I've got power to it, I suppose I'll be looking at a new pump?
If I've got power to it, I suppose I'll be looking at a new pump?
Trending Topics
Moderator
Joined: Jan 2001
Posts: 56,979
Likes: 2,734
From: Virginia
Yes, if you have power more than likely it's the pump. Just make sure when you test for power, you leave the pump in the circuit. In other words, you can unplug the plug to the tank and probe the plug for power that way, but there is a chance you might go through the whole routine of replacing the pump and it still won't work. The best way to check for power it to leave the pump plugged in and poke the wire to check for power.
This is good practice when checking anything on the vehicle. Leave the load connected.
This is good practice when checking anything on the vehicle. Leave the load connected.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
You have a lift pump in the tank, and a inline high pressure pump on that truck. If ther is no sound from the pump in the tank, or in the rail, check fuse first, then check the fuel pump relay under the hood. Early model efi had a lot of corrosion On the relay. The relay is located by the air cleaner housing. Usually the fuel pimp relay is green, eec is brown
Thread Starter
|
New User
Joined: Aug 2013
Posts: 13
Likes: 0
From: Fort Jones, Ca
I don't have a wiring diagram for this truck, so IF there's no power to the pump and I can't find a fuse, what would the power source be....from the ignition switch??
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
Pull the relay, and look at it real good. If all the terminals are there, good start, usually when they sit, they corrode. Use electrical terminal cleaner, and di electric grease.Power comes from a fusible link in the battery area. You will see a cluster of fusible link wires all together right by the battery. A tug will let you know if they are good, if bad it stretches, or is burned in half
Dave or Chris can probably put up a wiring diagram for you.
Dave or Chris can probably put up a wiring diagram for you.
Moderator
Joined: Nov 2007
Posts: 22,415
Likes: 92
From: Denver Metro Area, CO
I have 1981 factory wiring diagrams, they didn't have electric fuel pumps and relays and whatnot so can't help there. But search through the archives here, there are diagrams and pictures here....
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
True. The system went from 1985 to 1989, and the underhood wiring stayed pretty much the same until 1991. After that they changed under hood wiring to a power center, doing away with the fuseable links.
Moderator
Joined: Jan 2001
Posts: 56,979
Likes: 2,734
From: Virginia
Not the greatest diagram, but it's free. Start at the middle of the diagram at the top(fuel pump relay), and work your way back down. You will run into the fuel pumps going down in the middle of the diagram, and the computer is to the right of the diagram which powers the relay.
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
In that diagram, you see the yellow wire from the fuseable link (says hot at all times), goes to the fuel pump relay, then to the eec, then to terminal #1 on the engine control module. The fuseable link starts at the starter solenoid. It is in a group of fusible links, all breaking out from 1 16 gauge wire.
The fuseable link you are looking for is a 20 gauge, blue one.
Thanks Dave
The fuseable link you are looking for is a 20 gauge, blue one.
Thanks Dave