Ford F-Series Fuel Pump/Fuel System

scubarashscubarash Member Posts: 4
edited December 2013 in Ford
I have a 1990 ford f150 6cyl in which i have changed the fuel filter, both fuel pumps(have duel tanks), and i am still having a fuel pumping problem. The pumps pump for a long time before shutting off. The truck will not start until they shut off. Have checked the fuel lines fuel is pumping throught the fuel filter and also into the injectors and fuel is also returning back to its proper tank. Any ideas on what to replace now?


  • steve1doggsteve1dogg Member Posts: 7
    I am having the same trouble with my 1991 6 cyl. I have changed the fuel filter and the fuel pressure regulator -- no help. I'm beginning to think it is electrical. Have you discovered the cause yet on yor 1990?
  • jmyronjmyron Member Posts: 1
    I have a '94 F-150, extended cab, with a 4.9Litre straight six, overdrive tranny, dual tanks, and all of a sudden when I try and start it the pumps won't run to load for starting. I have checked the fuse box under the hood on the driver side and one of the yellow 20 amp fuses blows every time I turn the key. Could this have anything to do with it not cranking? I have no clue to what the fuse controls. Plus there are four or five black, 1" square fuses in this box also that I cannot tell if they are blown or not. I really need help here as this is our work truck and "no truck-no work" which means "no work-no money".
  • jnealjneal Member Posts: 247
    The blown fuse would have EVERYTHING to do with it not cranking. The fuse box should be labeled as to what circuit that fuse protects. If not, then your owners manual should show you. Find and repair the problem with that circuit and your vehicle should run once again.
  • hotrod_7292hotrod_7292 Member Posts: 2
    I am having the same problem with my 1992. Did you get it figured out?
  • steve1doggsteve1dogg Member Posts: 7
    Yes, I did. It was the EEC.

    I'd read many times that the problem is hardly ever in the engine control computer, so I kept looking elsewhere. I finally got to the point that it could possibly be the computer.

    I took the computer out, opened the covers and found some burnt and disconnected leads on 2 of the components -- two capacitors actually. I bought another box from O'Reilly's, plugged it in and it started right up.

    Hope I helped. Let me know
  • gedalsgedals Member Posts: 4
    what was the final solution?
  • gedalsgedals Member Posts: 4
    what was the final solution??
  • steve1doggsteve1dogg Member Posts: 7
    The EEC was bad. I bought a new one, installed it, and the problem was solved.
  • steve1doggsteve1dogg Member Posts: 7
    I replaced the EEC and that took care of it.
  • stan58stan58 Member Posts: 9
    I can't find a high pressure pump on my 1990 302.
    can you help?
  • steve1doggsteve1dogg Member Posts: 7
    My 91 Ford F150 has a 4.9 inline six and only has one fuel pump inside the gas tank. Sorry.
  • 0patience0patience Member Posts: 1,712
    Steve is correct.
    Gas engines have one pump. In the fuel tank.
  • stan58stan58 Member Posts: 9
    just for info: the 90 f150 has feul pumps in tanks. the 87,88 & 89 have low pressure pumps in tanks and a high pressure pump on the side rail. might come in handy.stan58
  • steve1doggsteve1dogg Member Posts: 7
    My 91 F150 has a pump in each tank, but none on the side rail.
  • ivan_techivan_tech Member Posts: 2
    I've got a 1990 F-150, 300 Straight Six, with dual tanks. I've been having a problem with the rear tank,for some reason it doesn't pressurize the system. The pump was replaced,and it worked for a time, but shortly afterward I had the same problem. I'mbeginning to think it's a wiring problem. Any ideas?
  • stan58stan58 Member Posts: 9
    Wish I could help but would only guess.
    I don't think wiring would keep pump from holding pressure, would look at fuel lines for leaks first.
    again just a guess, Good luck
  • lrj78lrj78 Member Posts: 5
    Hi. I have to depress the gas pedal when engine is warm to start the vehicle. Will not start if i don't. Black smoke comes from exhaust. Anyone know what the problem might be? thanks richard
  • gg0903gg0903 Member Posts: 1
    The motor which is a 5.8 liter gasoline
    won't run unless you feather the gas pedal. I changed the fuel pump and gas filter. It has
    30 pounds of fuel pressure when cranking the engine. My question is, why won't the
    engine start and stay running. Fuel regulator vacuum hose is dry. (it's not leaking).

    Please reply. Thanks for the help
    [email protected]
  • rbw289xxrbw289xx Member Posts: 3
    I would bet it is the EGR and is the check eng. light on?
  • junkman5junkman5 Member Posts: 1
    I bought a Ford F150 (1990)used. The back gas tank is no good. I want to remove it anyway, but when I do I can't get the lines run so there's no leak. Is there any way to do this with plastic lines without replacing the whole gas line system?
  • jim190jim190 Member Posts: 1
    My problem is that during driving, the truck acts like it runs out of fuel. Tank has gas. let the truck sit usually over night, and it will start. I have change the fuel filter many times, also pick up pumps and HP pump, no junk in tank. any ideas
  • steve1doggsteve1dogg Member Posts: 7
    Does your check engine light come on when that occurs? If you shut your truck off after that and then turn the ignition key to ON does the fuel pump not run for a short time like it should?

    The symptoms you described and the things I listed describes how my truck acted. Talking to people and reading up on it pointed me to not consider the ECM box -- that the ECM box hardly ever goes bad, but, after running into many deadends I eventually got a rebuilt ECM from O'Reilly's and it has been running like a top -- again.

    Not saying that is what you are dealing with -- just want you to keep your mind open to that possibility. God luck.
  • ivan_techivan_tech Member Posts: 2
    The rear fuel pump just doesn't come on.
  • wibble2wibble2 Member Posts: 1
    i have a 1995 ford F150. the front fuel tank pump died and i want to remove the fuel from that tank. i bought a self priming transfer pump but i can't seem to get it working. does the tank have a stopper or what am i donig wrong?
  • mwatkinsmwatkins Member Posts: 1
    Hello, I have a 1989 F150 with the straight 6 engine that has over 260,000 miles on it. The truck has always run well but I'm now having a problem with what I think is the fuel system. The truck will sometimes stall and run rough like it is running out of gas, and eventually quit. If I sit for about an hour, I can get it running again and it will run fine for a few days, then the problem repeats itself. I've replaced the fuel filter a couple of times and a mechanic has checked the fuel system pressure, but is unable to diagnose the problem. I'm not comfortable driving the truck now and would like some suggestions from anyone out there as to what the problem may be. Thanks, Mike
  • mickeymouse2mickeymouse2 Member Posts: 161
    Your Ford runs on 30-40 psi of fuel pressure. Using rubber fuel hose and clamps would be fine. Using the plastic lines is only safe if it is mounted on the inside of the chassi rail to protect it. Good Luck.
  • elephantelephant Member Posts: 3
    I have the hard plastic gas line and front tank connection went bad. The part is discontinued so can anyone tell me how to blank off the line so the truck will run on rear tank. I have tried plugging the line and clamping it to no avail. Thanks
  • mickeymouse2mickeymouse2 Member Posts: 161
    You din't specify year make or model but it doesn't really matter, Fords are pretty similar. First your only dealing with about 30-35-40psi of fuel pressure.

    Depending where the line broke depends how to do the fix. Autozone sells a mending kit for those lines that come with the new quick connect ect. If the line is damged or leaking, the easier fix would be to repair that section. If it is a return line, you can also bypass the first tank all together with a sutible size tee, rubber fuel line and clamps. If you choose to do the bypass, just make sure your splicing into the same type of fuel line on the other tank..,return or outlet. If you specify where exactly the line broke, or if it is the tank fitting itself, and more info on the type of vehicle and fuel system, such as does it have a selector valve ect. Any way hope this helped, good luck.
  • elephantelephant Member Posts: 3
    The truck is a 1990 F150 extened cab. The break is at the front tank quick connect. There is a y in the line about 12 inches from the break and it travels back to the front the rear tank. The front tank has never worked so I just need to cap that line that used to go to the quick connect at tront tank. Thanks for the help.
  • mickeymouse2mickeymouse2 Member Posts: 161
    Thanks for explaining it better. My recomendation is to buy the repair kit that will put a new quick connect end on the broken line. Then either reconnect it to the tank, or put a fuel filter on the end of the new quick connector. This will allow you to put a large vaccum cap and clamp on the other end of the filter to cap it off and keep it from leaking. This will also make it easier in the future if you decide to reuse that fuel tank and some point. Good luck with it.
  • elephantelephant Member Posts: 3
    Thanks for the help. I will let you know how it works out.
  • stan58stan58 Member Posts: 9
    I'd also like to know how it works.
    Thanks Stan 58
  • xman3xman3 Member Posts: 3
    have a 92 f150 8' bed with two tanks. need to remove the front tank pump-sender. does anyone know if this is possible without removing tank. looking at this seems possible, but do not know if length of unit will come all the way out.thanks.
  • mickeymouse2mickeymouse2 Member Posts: 161
    There is only two ways to remove the fuel pump assembly. Dropping the tank down or lifting the bed up. The fuel pump assembly and hanger is about 11 inches long and fragil. Do it the right way.

    Here is the trick. Drain the tank of fuel. Use motor cycle straps to secure the tank in place while you remove the two tank straps completely. Motor cycle straps almost work like a pully so you can lower the tank down slowly to undo fuel lines ect without breaking them. Good luck with it.
  • howie6howie6 Member Posts: 1
    I have a 1994
    f150 - trying to replace the rear gas tank. But I don't know how to disconnect those fuel lines. there is a clip on the lines themselves right in front of the gas tank and I have removed, does the lines then just pull apart?
  • mickeymouse2mickeymouse2 Member Posts: 161
    Ford uses 2 types of clips, metal and plastic. If you have the metal ones you have to use the disconect tools to release them. If they are plastic, you simply depress the 2 white in color tabs inward at the same time and tug on the line.
  • hd82hd82 Member Posts: 13
    My '07 F-250 message center is showing "WATER IN FUEL", this is my first diesel so I am ignorant to the maintenace and repair. Can someone help me with this message. From reading some of the posts I understand there is a drain on the filter, where is it, should I use some sort of dryer in the fuel?
    Thanks in advance
  • mschmalmschmal Member Posts: 1,757
    or Diesel Supplement on how to drain the water seperator.

    PS, if you waited for the message to come on, you waited 2 long. You should check your water seperator monthly at least.

  • rickmyster58rickmyster58 Member Posts: 4
    Rick here from Miami Fl. I just finished installing the front fuel pump in my 94 F150. I had to remove the drive shaft and the tank, cause the pump sits on top of the tank. my truck has two tanks also and on the inside of the cab by the plastic kick plate by the drivers side and passangers side are two reset switches for the fuel pumps. you may want to check this.

  • rickmyster58rickmyster58 Member Posts: 4
    I recently replaced the front tank fuel pump on my 94' F150. after installing it, I turned the key on without starting it, and the pump would run for about 4 or 5 seconds then turn off. telling me that it got up to pressure. after a few days of trying to trouble shoot why it's running rough, I noticed that now the fuel pump dosn't stop. just sitting in the drive way I've wasted about a 1/4 tank of gas. lots of black smoke and black soot all over the floor. I removed the 20 Amp fuse to the fuel pump and it idles perfect. can the pump be over pressurizing, hence the pressure regulator be bad? There are two what I call top hats, they look like a 1 to 1 1/2 inch silver can thats in-line with the incomming fuel line and one in the loop that feeds the injectors. which ione of these is the fuel pressure regulator?


  • mickeymouse2mickeymouse2 Member Posts: 161
    Your fuel pressure regulator is always mounted on the fuel rail with a vaccum hose connected to it. Look for raw fuel leaking past the diaphram and being sucked through the vaccum line, this might be the cause of the black soot. The other inline device you described is most likely a one way check valve. Please understand, Ford used numerous designs for duel tanks and there is also a lot of what is clasified as conversions, an added tank set up.
  • rickmyster58rickmyster58 Member Posts: 4
    thank you for your reply. I know that I have multiple problems with the truck again it's been sitting for 5 years. with no battery in it. after installing the new front tank pump, for the first day I got the engine to start, idle was check engine light. all seemed well. but now its eating full like crazy and thats just sitting in the drive way. can you direct me where to go to learn how to do the paper clip method the get codes from the computer?

    thanks again

  • rickmyster58rickmyster58 Member Posts: 4
    I would like to find out where I can get a ECM for my 94' F150. preferably re-conditioned.

  • sacplumbersacplumber Member Posts: 1
    We bought a 2001 F150 last year from my inlaws and two days ago it just stopped running. My husband believes that it is the fuel pump, which from what I am reading sounds like a very involved process to change, but his father indicated he just had the fuel pump changed out two years ago. Is it common for this to occurr with F150's or is there something else we should be looking at before we try changing the fuel pump?

    The check engine light is not on and we have already changed the filter.

    Thanks for any advice.
  • diehardforddiehardford Member Posts: 50
    Make sure the fuel cut out switch is operating. This switch cuts off the fuel pump in case of a collision. It is located inside the front seat passenger side kick panel . You should have had to unplug this switch to change out the fuel filter. There is a reset button on this switch make sure it has not tripped.
  • asalleeasallee Member Posts: 3
    I have a 1986 F250 XLT 4x4 w/4 barrel carb. Tons-o-miles. Duel fuel tanks that I have not been able to use (at least not the rear one). Front one was working fine. The truck started to run rough and use fuel like I had stock in Shell! Not good. Now it seems to get no fuel to the fuel filter (its clear glass) and I have never been able to hear a pump running. Is there a pump in both tanks? What is the device mounted on the frame rail beside the forward tank that has all the fuel lines and electrical connection going to it?
  • mike9408mike9408 Member Posts: 74
    I would suggest checking the fuel pressure regulator on the engine. It sounds to me like your regulator is returning most of the fuel to the tank, thus taking longer to shut off, especially since you are having the same problem with both tanks. Mike
  • mike9408mike9408 Member Posts: 74
    I would say that the device in the frame rail next to the forward tank is an external fuel pump or your selector valve. If the selector valve is not working you would only be able to use the fuel from the tank it is set on. Check your fuse pannel to see if the fuse is blown on either pump and the selector valve. If you find blown fuses, correct the problem with the wiring etc and replace the fuses, this should make both tanks useable. Mike
  • terny1terny1 Member Posts: 1
    It's an 88 f150 4x4 302 efi 5 speed stick dual tanks. I turn key on and the fuel pump under the cab makes a noise (no fuel pumpin) I can mess with it either by turning key on & off or squirt gas into intake and it will quiet (catch a prime) and start but smokes (black). It'll run great til the pump loses prime. Could it be filters clogged or is the pump going bad. It has always had a problem when rpms over 3000 like it runs outa gas but other than that it has been a great ride until now. I'm confused. Thanks fer any assistance. TWN...
  • help21help21 Member Posts: 2
    1986 f150 i pulled the line off of the pressure pump on the driver side frame turned key on to see if fuel would pump out and it did nothing,also checked the inertia button,turned the key on to see if the pressure pump worked , it clicked one or two times,if i put gas in the motor it will fire,it had two new fuel pumps put in the tanks a few years back and a little gas put in it to see if it ran and it did,but it has sat ever since,can u please help me?!
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