Expert Fuel Pump Opinions Needed!

[211Racing]

Just got a 2002 Tioga 24D. Base is a Ford e350 Super Duty van. Will turn over strong, but starts for only an instant. With the help of Starting Fluid, will run for several instants. Zero pressure at the fuel rail. Tightened the gas cap. Replaced the Fuel Pump Relay. Replaced the Fuel Pump Fuse. Replaced the Fuel Pump Filter. Checked and cleaned the Inertia Switch (button is down). Thumped the bottom of the tank several dozen times. Absolutely zero effect. I am reluctantly moving ahead to draining the 40+ gallons of fuel and dropping the fuel tank to replace the Fuel Pump. Can you think of anything that I have missed before I commit to this job? Thank you for your help. (And ... I checked to see if I could access the Fuel Pump through the floor in the back of the RV. Lovely thought, but not possible).

[Gdetrailer]

Grit dog wrote:


And he's assuming that one could pull fuel through the dead pump as well. BTW, pulling fuel doesn't work near as well as pushing fuel, hence the reason electric pumps are generally located at the source (in the tank).
A well intentioned suggestion, but OP hasn't even responded. Either the pump runs (makes noise) or doesn't. Presume doesn't but he hasn't confirmed. And if it does and aint pumping fuel, then its still shot, but at least can be diagnosed as the pump and not something upstream in the power supply.

Poster may have assumed it will pull, don't know, but I suspect the poster that mentioned using an external pump was to help diagnose the issue. Well intentioned but doesn't prove that 1, the ECM is good, 2 the wiring to the pump is good, 3 pump is good..

All three must be good for OP to get fuel pressure at the rails.

As far as hearing the pump run, generally you will never hear them run as the more modern electric pumps are not loud and don't sound like a grinder any more..

Was doing some research, on 2002 Ford pickups there is a fuel pump module that was mounted at the rear of the truck above the spare tire.. Not sure if the vans are setup that way.. But worth a look see to verify that all the connectors are in good condition.

I had a 2003 F250 with 5.4 and a few other yrs of 5.4 engines and am familiar with them.. Never had fuel pump issue but did have intermittent fuel gauge issue on the 2003..

[Gary45]

211Racing wrote:

Gary45 wrote:
My E350 based motorhome has a lift pump in the tank and a fuel pump mounted on the frame just behind the front wheel. If yours the same check electrical connection.

That's very interesting. I replaced the fuel filter just behind/below the driver's seat. Didn't see a pump. What year is yours? I assume you mean the left front wheel? I'm not seeing that set-up for a 2002.

Mine is a 1986 , the gas supply is set up like fuel injection even though it has a carburetor, there is a pressure relief valve near the carburetor so constant flow through return to tank.

The pump is mounted on the frame below drivers seat.

I read somewhere it was done that way because in a motorhome the gas tank is farther back, also with the constant flow through the lines less chance of vapor lock.

[Grit_dog]

211Racing wrote:
Drained the tank. There was a very convenient plug on the bottom of the tank. Magnetic. Did have a fair amount of rust/debris on it. I've seen worse on oil plugs for old motorcycles. Gas was brown for the first several seconds. Will drop the tank whenever it stops dripping.

Drain plug?? Score one for the good guys!
Gotta think it was added by someone, aftermarket, maybe thinking ahead on a vehicle that could would be stored for periods of time.

[211Racing]

Drained the tank. There was a very convenient plug on the bottom of the tank. Magnetic. Did have a fair amount of rust/debris on it. I've seen worse on oil plugs for old motorcycles. Gas was brown for the first several seconds. Will drop the tank whenever it stops dripping.

[Grit_dog]

Gdetrailer wrote:

John Burke wrote:
You may want to try an aftermarket electric fuel pump to help figure out if you have a in tank fuel pump issue before spending time and a fair amount of money for a new pump.
There must be a rubber line somewhere, by the filter or between the frame and the motor. The fuel filter below the seat would be a good place. Just put an electric fuel pump in line where the filter is and run it off a jumper wire, extra battery or a battery charger. If it is all steel line you can put a piece of rubber line over the steel line and clamp it on.
You can get a pump from Amazon from 12.00 to over a 100.00. just get a cheaper one.
This way should be a lot easier diagnostic tool than dropping the tank and putting in a expensive replacement pump.

While you could do that, it doesn't prove that the pump, ECM or wiring to the tank is good or bad.

Not to mention most of those aftermarket fuel pumps often will not have as much pressure as the OEM and may or may not even start the engine. This isn't a carbed engine and OEM fuel injection systems tend to require pretty high pressure just to get then to start.

To "prove" whether it is ECM, wiring or fuel pump with an external pump, OP would still need to drop the tank to access the OEM wiring connector on the tank.

OP has a 20 yr old vehicle which has been sitting for some time. Fuel pumps do go bad and it has enough age and sit time that makes it highly possible the pump bearings has rusted and/or frozen. Or the internal tube could have a pinhole(s) in it or broken off due to rust from sitting around.

Once OP has tank dropped they could bypass the ECM and wiring by disconnecting the wiring harness from the pump and connect the pump directly to the battery (observing polarity and not putting battery power on the tank sensor wires so they will need to figure out which wire is which) and see if they get pressure at the rail.

And he's assuming that one could pull fuel through the dead pump as well. BTW, pulling fuel doesn't work near as well as pushing fuel, hence the reason electric pumps are generally located at the source (in the tank).
A well intentioned suggestion, but OP hasn't even responded. Either the pump runs (makes noise) or doesn't. Presume doesn't but he hasn't confirmed. And if it does and aint pumping fuel, then its still shot, but at least can be diagnosed as the pump and not something upstream in the power supply.

[Gdetrailer]

John Burke wrote:
You may want to try an aftermarket electric fuel pump to help figure out if you have a in tank fuel pump issue before spending time and a fair amount of money for a new pump.
There must be a rubber line somewhere, by the filter or between the frame and the motor. The fuel filter below the seat would be a good place. Just put an electric fuel pump in line where the filter is and run it off a jumper wire, extra battery or a battery charger. If it is all steel line you can put a piece of rubber line over the steel line and clamp it on.
You can get a pump from Amazon from 12.00 to over a 100.00. just get a cheaper one.
This way should be a lot easier diagnostic tool than dropping the tank and putting in a expensive replacement pump.

While you could do that, it doesn't prove that the pump, ECM or wiring to the tank is good or bad.

Not to mention most of those aftermarket fuel pumps often will not have as much pressure as the OEM and may or may not even start the engine. This isn't a carbed engine and OEM fuel injection systems tend to require pretty high pressure just to get then to start.

To "prove" whether it is ECM, wiring or fuel pump with an external pump, OP would still need to drop the tank to access the OEM wiring connector on the tank.

OP has a 20 yr old vehicle which has been sitting for some time. Fuel pumps do go bad and it has enough age and sit time that makes it highly possible the pump bearings has rusted and/or frozen. Or the internal tube could have a pinhole(s) in it or broken off due to rust from sitting around.

Once OP has tank dropped they could bypass the ECM and wiring by disconnecting the wiring harness from the pump and connect the pump directly to the battery (observing polarity and not putting battery power on the tank sensor wires so they will need to figure out which wire is which) and see if they get pressure at the rail.

[John_Burke]

You may want to try an aftermarket electric fuel pump to help figure out if you have a in tank fuel pump issue before spending time and a fair amount of money for a new pump.
There must be a rubber line somewhere, by the filter or between the frame and the motor. The fuel filter below the seat would be a good place. Just put an electric fuel pump in line where the filter is and run it off a jumper wire, extra battery or a battery charger. If it is all steel line you can put a piece of rubber line over the steel line and clamp it on.
You can get a pump from Amazon from 12.00 to over a 100.00. just get a cheaper one.
This way should be a lot easier diagnostic tool than dropping the tank and putting in a expensive replacement pump.

[allbrandauto]

try taking a rubber mallet and bang on the tank while somebody cranks it over if it fires up replace fuel pump

[211Racing]

I run gas. 2002 E350 v8 Triton 5.4

[RLS7201]

Gary45 wrote:
My E350 based motorhome has a lift pump in the tank and a fuel pump mounted on the frame just behind the front wheel. If yours the same check electrical connection.

Can we assume that you have a diesel? That's the only engine that I know of that uses a lift pump.

Richard

[211Racing]

Gary45 wrote:
My E350 based motorhome has a lift pump in the tank and a fuel pump mounted on the frame just behind the front wheel. If yours the same check electrical connection.

That's very interesting. I replaced the fuel filter just behind/below the driver's seat. Didn't see a pump. What year is yours? I assume you mean the left front wheel? I'm not seeing that set-up for a 2002.

[Gary45]

My E350 based motorhome has a lift pump in the tank and a fuel pump mounted on the frame just behind the front wheel. If yours the same check electrical connection.

[211Racing]

Here is where we see who has been to sensitivity training and been schooled on always telling the truth, no matter how unpleasant (didn't help ... got divorced just the same). In truth, I was thumping on the black water tank, not the fuel tank. Fuel tank is mid coach. Water tank is far aft. Fuel tank is considerably smaller and thicker walled. I've got all kinds of jacks and lumber to put into play. If I can figure out how to jack up one set of rear wheels at a time and place a pair of plastic ramps under them, this fuel pump replacement business will be much easier. As it is there is very little room.

[wa8yxm]

211Racing wrote:
Thank you to all. I do have a motorcycle jack and will see how to work it under the tank. Challenge is that the tank is 55 gallon and seems quite flexible when pushed on (thumped) from the bottom. It appears flush-mounted to the underside of the RV, so there's no peeking up there with a cell phone camera to get familiar with the layout/pump/lines. I have cleaned and/or replaced both of the frame to body grounds, but will look today if there is a specific ground on the tank.

You might want to lay a 3/4" plywood on top of the jack. use some 2x2 or 2x4 attached to the bottom of the sheet with screws (Down into the sheet) to make sure it does not slide off the jack if there is a possibility of that. Spread the load over the entire bottom of the tank (not sure how big the jack's top is) I've done much the same with automotive tanks using a standard floor jack and lumber to support tank.

But you want to be 200% sure it won't slide off cause that's a 1st class pain in the operating system.