Why the frame mounted fuel pump might run after the key is turned off? Then when you turn the key on it may or not run. If it does run it keeps running. shouldn't this shut off after pressurizing the line? is their a pressure switch in the pump that's failing? This has the 3 pump system...
View 4 RepliesI have an 87 F150 4x4 4.9L EFI with a single tank. Fuel pumps keep running even when the key is off. I tried swapping relays but the problem still exists. The engine will start and run OK for about 15 secs. then die. I installed a new low pressure pump, high pressure pump seems to be OK. I also installed new fuel filters. I dont want to just throw parts at this truck, where do I go from here?
View 4 RepliesIt started out w/ my wife swapping from the front fuel tank to the rear tank due to the fuel qty getting real low. Then the next day when I drove it I had bad fuel qty and amp meter indication, I found a blown fuse on my fuel qty/amp meter gauges. I replaced the fuse and got my indications back. Now I hear my front tank fuel pump is running constantly when selected to its position. Its now full of gas and still runs constantly. The rear tank/pump operates normal. I am wondering if I ran that pump empty and lost its prime? What is the best way to burp it?
View 9 RepliesI've had a fuel leak near the pump of my 79 F150 with a 400 for some time. I didn't know exactly where it was coiming from, but fuel was being sprayed on to the oil filter from something near the pump. I assumed it was the steel line, and that it had rusted through or cracked, and was going to replace it when I had a chance. I was poking around today though, and realized that the fuel was not leaking from the line, but from a hole in the side of the mechanical pump.
For someone who knows what these pumps look like, there is a horizontal cylindrical bump out near the top of the pump, on the side of the pump that is away from the engine. The fuel is spraying in a mist out of one side of that. To me, it always seemed to be a screw channel, but I didn't think the pump was 2 halves put together? Need to know more about my pump, what that bumped out section is, or why/how fuel could be spraying out of it.
I have an 87 f150 inline 6 efi. The truck will not rev over 2000 rpm even when idling. It has a new fuel filter. What this could be?
View 2 Replies1987 f150 302 4spd 4x4. When I bought the truck 4 years and 12K miles ago the orig owner had just installed a new front pump (in tank) and new switch thing on the frame rail. He said shortly after that the rear pump stopped working so he just ran off of the front tank. That's what I've been doing also except as of the last few months it has started to leak from the rear tank (I don't ever put gas in it and was empty when I bought it) and dies periodically from time to time? Where the leak could be coming from. I do suspect the dying has to do with the leak though.
View 3 RepliesI just purchased an 87 f250 w/ a carb'd 460. I purchased it with the mech fuel pump swapped out to an electric. The previous owner states that they gave him the wrong electric pump and I should exchange it for a different one. The reason for him putting it on was to get it running for me to hear it run.
My question: Is this even recommended? I wouldn't mind staying with an electric pump up front. If it is recommended, what would be a suitable pump to replace it with, as in flow/feeding characteristics?
Also, it only feeds from the rear tank, which also has a bad fuel pump. I'd like to get both tanks functioning again. I'd rather not deal with the tank switching valve due to what I've read about them. Has anyone ever hooked up a manual valve and just switched tanks that way? I've searched this site extensively and couldn't find anything. I know I'm not the first to have thought about it.
I have a '77 F250 with a 460. (Under edit) It has a holley 750 carb. (under 2 years old). It ran fine for about 2 years and now all the sudden it seems to not get enough fuel. I have a clear fuel filter on it and you can see that it is full of fuel when I first start it up. Just letting it sit there and idle after about 5 minutes it starts to show air coming through the lines and it gets worst the longer it runs.
If I take it out on the road and drive 55 it will be about 1 or 2 miles and it acts like it's not getting fuel. I stop and open the hood and check the filter and it is empty. What could cause this? I took it to an old Ford machanic and he has checked the fuel pump, fuel lines, sending unit, and gas tank. He is at a loss. I am no mechanic, but I am mechanicly inclined. I can't see it would be that hard to figure out. What do I do?
My vehicle:
1976 F150 2wd Extended cab
390 4bbl
c6 transmission
4BBL Edlebrock Carb
Dual fuel tanks, only rear main tank connected
My problem: For the first year I owned the truck, everything ran fine and it started up really quickly even after it sat for a few days or a few weeks. I have since, for about the last year or so, had to crank it for 30-45 seconds to get it to start. This all started around the time my fuel pump went out. I replaced it with an Airtex fuel pump from Autozone. I also installed a glass in line filter before the carb in front of the distributor.
I noticed that after about 4-6 hours, the fuel had drained out of the filter and that's when I would have to crank it forever to get it going. It also seems like there is no fuel in the carb as it doesn't even try to start when it first gets cranked. I thought this was a bad pump, so I bought a new one last week and tried it again. Sure enough after about 4-6 hours, everything is empty again and it takes forever to start it. So it's not a bad pump, or so I think.
The other day I backed it into my driveway and left it, something I never do. I checked about 4 days later and there was still fuel in the filter. This makes me think that gravity is making it drain back to the tank.
Is there something that would cause this? Also I have found a one way fuel check valve online that is supposed to remedy this type of problem. Do they work for this situation? Or is there something else I should be doing to fix this? It has taken a bit of a toll on my starting system having to crank so long all the time. I have so far had to replace my starter, starter solenoid, and all the battery cables, starter cable, terminals, etc. due to excessive wear.
The valve I found is here : [URL] .....
I've got a 01 f150 yesterday stopped running (like it ran out of gas). Has half a tank. Fuel pressure at rails good but truck will not turn over. Fuel pump and filter less than year old.
View 1 Replies1993 F150 302. What does the fuel canister purge solenoid/vac play in the furl/emissions arena?
View 5 Repliescant figur this out have no signal to injectors and no power at fuel pump 88 f150 5-0
View 2 Repliesfor the past week we have been trying to figure out what is wrong with our truck. We recently bought it and it ran fine. Then got in a minor accident just a fender bender and it started acting up so I got towed to garage. First it would run when cold, but when hot fuel pressure would drop to 28 psi.
So I put new fuel pump, it started but still did the same thing hot 28 psi fuel pressure shuts off. So I put regulator on it, then had 0 fuel pressure won't even start. So got a another regulator thinking I got a bad one, still 0. Checked relay, there fine. I'm gonna check lines and see where fuel stops at but everything is new on it.
1994 150 300 6. parked truck after lunch finished work and it wont start no fuel comes out of the valve. Can't get the pump to work even when jumping the 6 pin. heard the relay click still nothing. Checked the inertia switch it wasn't popped. Took the pump out jumped it straight from the battery pump works . I know there has to be something i am missing...
View 7 RepliesI'm looking at replacing the fuel lines in my 94 F150 and the big question is what to do with hooking up to the fuel lines coming out of the fuel pump hat and the fuel rails? Ford uses a specialized pressure fitting on it's custom fuel lines. I think there may be some third party fittings that would replace these, but I'm not sure. I could use a standard hose and cable clamps, but I just don't trust that kind of connection for a fuel line.
View 5 RepliesI have a 1986 F150 6 cyl, dual tanks, no AC, manual fuel pump. Just recently, I have been having issues with the tanks. At first it seemed like the back tank was siphoning from the front tank. Now I have fuel coming out of my front tank filler neck. When I open the back tank gas cap, there is enough pressure to spray me with gasoline. I am not familiar with the fuel delivery system of my truck ...
View 2 RepliesI recently purchased a used 1999 F250 Super Duty with about 150k miles on it. The truck runs great and I have no complaints but there are a few things that need to be taken care of. It looks like there is a very small fuel leak where the filler neck ties into the rubber hose that runs into the fuel tank. There is a thin film of diesel along the side of the tank, on the leaf spring, the air bag and various other places. Nothing is dripping. I want to drop the tank and replace the hose. The Haynes manual says to depressurize the whole fuel system--is this really necessary if I don't plan on doing anything to the system aside from dropping the tank?
View 2 RepliesStuck 398 miles from home. Car kept losing power, running out of fuel (even though I had a quarter tank). Stopped and filled it, but could only barely get to next exit. Step on gas- no go. Let off gas, car catch back up and run. Wife noticed definite new sound in back. Took her many miles and comments before it finally sunk in and I remembered the same groaning noise from a fuel pump going out on a cabrio. So, fuel pump bad.
Am preparing to go out and jump terminals, as per bentley manual. That should tell if it is transfer pump or fuel pump. My main concern now is are the pumps under the rear seat or in the trunk?
By the way, I made it to a motel (lucky enough one that accepts pets!)
This van has had a couple of fuel pumps, no surprise there, and i need to look through my paperwork and find out how many miles the current one has on it, but it has the STRANGEST habit I've ever had on any vehicle. Starts fine, runs fine, no fuel pump noise when van is running, and when you turn it off, the fuel pump creeks on and off for several minutes.
I mean a strange creaking noise almost like a shorted electrical device or a vehicle's brakes when you park it on a hill and the breaks creak as it settles into place. I'm probably doing a lousy job of describing this but i don't know how else to describe it!
ALSO, if you lay under the van and wait til it stops creaking, you can tap the bottom of the tank and it will creak for a few more seconds. You can tap repeatedly and make it creak more. Is it about to explode? Can i trust it on a road trip?
I just bought another 1991 Ford. This one is a 1/2 ton XLT Lariet with the 302 and for the first time I own a short bed. I also have a 1991 F-250 XLT with a 460 and a 8' bed.
Here is the problem, ( I think) it will not run or at least not for long. The fuel pump, which I am guessing is in the rear tank will not stop running. On the F-250 the pump stops running after a few seconds after I turn on the key.
Where should I start to find out my problem with the fuel system?
I have a 1994 Ford 460 motorhome with a intank fuel pump that quits when it gets hot. so I was thing of butting a heavy duty in line pump on and just pull it through the old pump can this be done safely. Or is it best to drop the tank and just put a new fuel pump in.
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