Question about 1986 Ford F150 SuperCab

2 Answers

86 F150 with 5.0. is not getting fuel

I have checked the pumps and they are good. I tried to check relay, but not sure which one it really is. I bought a Chilton manual and they say to ground the service plug to get the pumps woriking and that does do the trick. However, it does not seem to tell us what may be the problem other than the PCM. If I disconect the jumper wire that kicks the pumps on, it dies. I pulled a relay on the firewall, It died. So I think I may have the right relay and it is good. I also believe the inertia switch is good since I can get it started. What else may it be?

Posted by on


2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.


    An expert whose answer got voted for 20 times.


    An expert who has answered 20 questions.

  • Expert
  • 130 Answers

These are the relays located by the solenoid usually it is a connection problen in the connector check the red and brown wire even it wont look bad if you stick a test light in and you hear it click then you know you have a connection problem

Posted on Feb 09, 2009

  • Level 1:

    An expert who has achieved level 1.


    An expert that has over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 10 Answers

Jump across inertia switch to be sure thats usuallyyhe first thing to go

Posted on Feb 09, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

My fuel pump is good, but foe some reason it's not getting any electrical power from the line....what should I do?

Well Jason you could have a bad fuel pump relay in the underhood electrical center . The PCM - powertrain control module turns on the relay . An your vehicle has a anti-theft system probably ! Is there A security light lit on the dash ? If not pull the fuel pump relay out of the electrical center an check for power an grounds , there will be two grounds an one battery voltage an one open . The open will be power when cranking the engine , this is the control side from the PCM . If you look on the side of the relay there should be a circuit diagram , an on the bottom the pin's should be marked 30 , 87 this is the fuel pump side of the relay. 87 is battery voltage , 87 goes to the fuel pump . Pin's 85 , 86 . 86 is ground an 85 is power from the PCM when cranking ! GM Fuel Pump Relay Testing

May 09, 2015 | 1997 Pontiac Grand Prix

1 Answer

Inertia switch location on 86 monte carlo 4.3

Sorry , no Inertia switch on 86 Chevy Monte Carlo , so you have no fuel ? Did you check the inline fuse or fuel pump relay ? Near the battery is the fuel pump relay an the inline fuse !

Apr 22, 2015 | 1986 Chevrolet Monte Carlo

1 Answer

Electrical problem with fuel pump

disconnect the pump by the tank and put power directly to the wires to check it. You should hear it whining. If you do. the pump works. next check the pressure at the engine, you may have a plugged filter. if you find the wires from the front to back of the car has no power after checking for power on all components, ( the relay socket should have power on 2 sockets when the key is on) make sure this is so. If its not you need to make sure you get power on terminal marked 30 on the relay and either 85 or 86 (one will be ground the other power) if all that checks out you have a wire broken leading from the relay to the fuel tank.

Mar 13, 2014 | 2000 Kia Sportage

2 Answers

I have a 97 chev suburban 350 and no power to the fuel pump ,new fuel pump,fuel pump relay fuse is new,checked all wiring no cracks or breaks all along from fuse s to pump all good,just when i turn key is...

I would interrogate the fuel pump relay socket with a voltmeter or test light. There should be one hot terminal from the ecm b fuse. There should be a terminal that has chassis ground for the relay coil. The positive terminal for the relay coil comes from the ecm when the key is on. If you have trouble interpreting the results of these troubleshooting steps, feel free to comment back. The circuit is on the right of the diagram about 1/3 down the page.


Sep 28, 2017 | 1997 Chevrolet Suburban

2 Answers

I have 1994 oldsmobile sierra cutlass that i have recently changed the the fuel pump and the relays , and im getting power to the float and not the pump itself, i retraced the wire harness from the fuel...

Below is a picture of the fuel pump relay and the "plug" plug by numbers. See if you are geting power where the number 87 would be if it was plugged in. If you are not geting power there, check at the starter. There is a fusible link coming from the starter (red wire) if you are getting power on both sides of where the fusible link is, follow that wire further and there is a 15 amp inline fuse. If all is good there, have someone turn the key to the on position while you are checking for power at the number 85 slot. This is the power supply directly from the computer. It will only energize for about 2 seconds. If there is no power there, check the wiring from the vehicles computer to make sure all is good. If all is good you may be looking at a bad computer. You can also check to make sure you have a good ground at the number 86 slot and the black wire at the fuel pump. That ground is located on one of the transmission mounting bolts. All of this information is based on you having the 3.1 liter engine. If you have the 4 cylinder engine, not all of this applies. I just went with the most common engine for your vehicle since you didn't say which engine you have. If you have any questions or need any wiring diagrams or if you do have the 4 cylinder, feel free to email me at Hope this helps and good luck.


Oct 30, 2011 | 1994 Oldsmobile Cutlass Ciera

1 Answer


O.K. this is going to be long but stick with me.
The gray wire that goes to the plug at the sending unit is the one to run the pump. We need to get power to this wire. This wire runs to the fuel pump relay. The relay has 4 pins one is the gray wire-one is the 15 amp power for the pump that has battery voltage with the key in the run and start position. one is ground and one is the relay trigger from the ecm. Pull the relay and look real close on the bottom side of it by the pins there will be numbers 30,85,86,87. 85 and 86 control the relay 30 is the power from the fuse and 87 is the gray wire going to your fuel pump. If you use a test light and see if it lights up between pin 85 and 86 when you first turn on the key (should come on for 5 seconds or so). If not we have a problem on the computer side. If so go to #2 below. If not ground test light and try 85 then 86 if it lights up on one of them when you first turn on key the other post (of 85 or 86) has a bad ground.
#2 So we now know the relay circuit is good Turn key on and check for voltage between post 30 and ground. if there is voltage then run a jumper wire from battery voltage through a 15 amp fuse to post 87 if the pump comes on its the relay if it stays off then there is a open in the circuit from the relay to the pump. don't forget to check for a good connection where the wires go into the plastic on the top of the sending unit. reply if I typed to fast and I can walk you through any step you have problems with.
Good Luck and God Bless

Jun 07, 2011 | 2001 Pontiac Grand Am SE

1 Answer

!988 Jeep Cherokee MPI fuel pressure problem. New everything on/in the fuel system. Can only make it run with a jumper wire from the fuel pump to the battery. Any ideas?

Have you checked the fuel pump relay. If you haven't locate the relay and jump out pins 30 and 87 (there should be a diagram on the relay or if you look at the bottom of it, the pins should be numbered, jump out the corresponding sockets in the relay housing). If the fuel pump turns on when you do that you've verified the power feed is good and the wires to the fuel pump are good. Now with a digital multimeter check that there is battery + on pin 85 or 86. If that checks out, when cranking make sure there is a good ground on the opposite pin (if pin 85 had + on it, pin 86 should have a ground). If all that checks out you can suspect the relay is faulty.

Aug 26, 2010 | Jeep Cherokee Cars & Trucks

2 Answers

I have a 1994 ford thunderbird and it has a problem of sputtering and then stopping after about 45 minutes. It sounds like its not getting enough feul. If you let it set for about an hour or two, it will...

All of your symtoms point to a clogged fuel filter. The filter is located underneath the car below the passenger's side door. It will have fuel lines connected at either end. You will need to depressurize the fuel system by either disconnecting the fuel relay or disconnecting the wiring harness for the fuel pump. The bolt is clamped on the frame so you will need to unbolt the mounting bolts. Then you will rotate the fuel filter our and uscrew from the fuel lines.

Aug 25, 2010 | 1994 Ford Thunderbird

2 Answers

Have no power to the fuel pump. Truck will not start. what to do next?

1. make sure you really have no fuel delivery. open a line convenient for you as in cold start injector or fuel filter, disconnect ignition coil lead and crank away a bit to make sure you're not getting fuel.
2. I assume you're getting spark.
3. check efi fuse in main relay box passenger side inside right fender. if good check that you have juice at the Co relay hidden in the passenger kick plate. its the white-red terminalwhich delivers the current. the Circuit opening relay is really the main enchilada for getting the pump up and adam.
4. still no go. you have to address the Co relay itself. test terminals with ohm tester. also you can jump wire the Bp fP terminals in the diagnostic connector on the side of the main relay and see if the pump goes.
5. and lastly it might be the pump itself

Jun 17, 2009 | 1991 Toyota Pickup

1 Answer

86 volvo hesitates/stalls problems

Check the fuel pressure regulator. Its a vacuum assisted device that sits on top of the engine. Pull the small vacuum hose off the regulator and see if it is wet with gasoline. If so replace the regulator - AutoZone $60. Let me know.

Dec 16, 2008 | 1986 Volvo 740

Not finding what you are looking for?
Cars & Trucks Logo

183 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

77499 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22306 Answers


Level 3 Expert

5610 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides