Fuel Pressure Nightmare

[Jrzfly]

I bought a 1993 Ford E350/460 motor Shasta RV this year. The RV sat for a long period of time before I bought it. So first thing that I had done was have the fuel tank cleaned out and a new fuel pump and filter installed. A week after I got it back it was hard for the RV to get above 25 mph. It would bog out and back fire at the engine when you would push the gas pedal to try and excelerate. I had the cat converter looked at and it wasn't clogged. After further tests it was not getting enough fuel pressure. The mechanic drops the tank again and says the fuel pump was defective. Puts the new one in and RV drives good for half an hour and looses fuel pressure again. Take it back to the mechanic and he finds debri in fuel pump. He says the tank still has something in it. So I tell him to order a new tank, he proceeds with ordering with Ford per my VIN number and the Tank doesnt fit. So he can't find the right tank and tells me he has a better guy to clean the tank out. So back to square one. All this being said my RV has been off the road all spring and summer. Anyone have a similar problem or order a new tank before? VERY frustrated.

[tioga28c]

Our 1990 e350 ford did this when we would go south. But ran great up north . On the second time being towed for this in Arkansas the wrecker operator said to use a fuel treatment as they use higher amounts of ethanol in the south than up north due to the water content in gas up north would freeze but would work in the south. I use Lucas fuel treatment each refill and it run great . the pump was overheating due to ethanol being not as lubricating as non ethanol. .

[Travelcrafter]

I had an little ford Currier I bought new in the early 80's it would run like a top for 2-3 thousand miles thin just quit. Id pull of the road and set for a while and it would start up and run again for 2-3 thousand miles I took it in on warranty and told the mechanic I thought something was in the fuel tank so the changed the fuel pump, next time they changed the whole wiring harness each time they worked on it i told them i thought something was in the fuel tank. finely I had had enough and dropped the tank in my front yard. in the bottom of my tank was large peaces of paint flakes floating around that came from my filler tube why the inside of my filler tube was painted is beyond me but the chips would slosh around till it got sucked up against the suction tube cause the truck to starve for fuel then when i shut the truck off it would brake the suction and sink to the bottom of the tank until it got sucked up again. I knew then they never once checked it.there are a few companies out there that will acid dip your fuel tank then put a chemically bonded liner in there that will encapsulate any rust left in the tank. There are also kits you can get for DIY projects; at any rate I wish you good luck and hope a remedy comes along.

[j-d]

Glad to hear that! This should not have been so difficult, but we've had several instances where it was.
Now enjoy your coach!

[Jrzfly]

Final Update, I Hope. Had the Fuel pump replaced for the third time. Took a 10 hr trip with no problems. Looks like ford had a bad batch of fuel pumps.

[svtkev]

sounds like vapor-lock to me

[triple602]

If not crazy expensive I'd replace the tank too.

[gkainz]

I heard from a friend who went thru the same thing that Ford received a big batch of faulty fuel pumps ... many DOA or very short-lived. His 3rd replacement pump proved to be a good one.

[Jrzfly]

The mechanic says it has to be a bad fuel pump. We are gonna replace it for the 3rd time.

[Big_Katuna]

There was a post years ago by Dirtrod. He had a full install with wiring diagrams on his F53. He left his OEM pump in place and added the aftermarket pump.
I think he disconnected it but I could be wrong. The class A mod Boundersomething used to have Dirtrods right up.

[j-d]

The Two-Pump Strategy will work if the in-tank (original) pump is WEAK. It won't work if the original pump has failed. That's for the Fuel Injected Fords using high pressure pumps. The older low pressure in-tank pumps (for carbureted engines) allow you to pull fuel through them even if failed/not running.

[Big_Katuna]

People have added a pump on the frame near the filter. They leave the in tank pump in.
NAPA , Summit,etc sell pumps for EFI applications. Needs to be wired thru your crash detector like the in tank.

I had pump issues too. Once the pressure drops below 32 PSI the ECU goes wacky.
Turning the ignition off then on resets it. I got proficient at it too.

Mine was fine at sea level in Florida. Any altitude it acted up. Two pumps.
Sold it. I strongly disliked my F53 460.

[Jrzfly]

Nother update: Mechanic dropped tank and did some fuel pressure testing. Tanks clean, pump and filter clear. Still losing pressure or not receiving enough to accelerate. He is moving on to check possible electrical problems, didn't like how the relay looked. Any suggestions out there?

[Harvey51]

There ought to be a way to run the fuel pump with the line disconnected at the filter and watch what flows out, perhaps onto a large cloth filter over a pail. Run a few gallons through and maybe it will get rid of all the crud. At least you would know if the problem is still there. Could even do it with the tank off and not put it back unless the crud flow ends.

[carringb]

On your rig, fuel delivery is determined by Manifold Absolute Pressure. Your symptoms however sound exactly like fuel starvation. An obstructed fuel pump or filter will still slow enough to start, but not enough to deliver power at cruising speeds. Your problem could go away after a restart simply because shutting everything off lets the flakes fall away from the strainer.

Delamination is not a rare problem unfortunately, and bio-fuels (i.e. ethanol) seem to contributor, as some components were never designed for it. It could also just be plain old rust, if water had ever gotten in there previously. Either way.... fuel pumps and fuel filters don't normally plug up like that repeatedly, unless there is a problem with the tank.