Relate your Ford chassis fuel pump troubles and fixes

[GypsyR]

I wouldn't with my setup shown and an electric ratchet I can go from putting the jack under there to having the tank down and pump out in just under 15 minutes.
I cheat just a little. The ground drops away from where the rear tires are resting which gives me and extra six inches of clearance to work with under there.

At one time I had the fuel pressure gauge leak on the engine some and the smell went back into the coach some. Wife raised ungodly heck. Took me three days of running fans with open windows before the smell was gone enough to satisfy here. Cut a hole and let gasoline fumes into the bedroom? Not to mention that when you pull a pump it always dribbles some fuel. Nope, not me. Keeping all that smell under the coach.

For other people who might be differently abled or lacking in equipment making a hole in the floor may well be the better path. Just don't cut into your fresh water tank or something like that one guy did!

[MarvinG]

Right, don’t cut a hole in your fresh water tank like I did!

The flip side though, is, on mine, the leveling Jacks would have to be removed before I could get the fuel tank down. So I did cut the hole from the top. The only thing I would do differently next time is remove the fresh water tank first!

Having the access top “hatch” was a great blessing when my first replacement fuel pump failed and I was stuck alongside the road. I drained the fresh water into the ditch, opened the “hatches” and reinstalled the old, marginal pump in about an hour.

If I could have the tank down as quickly as GypsyR can his I would never have cut the hole I agree.

Gypsy R: Wow! I’ve never seen such crud as that. When I pulled my first pump out I was amazed at how pristine and clean everything was inside. When I replaced the first new pump with my old one, and again the old one with the last replacement, I found the system not as pristine as originally. Even with cleaning the entire area with brake cleaner before pulling the tank some I managed to introduce a slight amount of sediment into the tank. But nothing to compare with that. That picture is just amazing.

[TommieG]

It's a thing of beauty! A brand new aluminum fuel tank for hazel. I got this beauty from Boyd welding in Ocala Florida.

[98FPA]

This has been an interesting topic for me since I just experienced the same somewhat symptoms. I just went to Colorado on a 400 mile trip and when I was reaching the campground my MH kept dying. I would get it started, it would go a short distance then die again. Finally got to the campsite and got set up. While after a couple of days I exchanged my locking gas cap to the OEM Ford gas cap, started my engine and ran it for about 20 minutes; no problems rans smooth, idled good etc. Waited a couple of more days and decided to take it on a little test drive around the campsite and it ran like it normally did. On the way the way to Colorado temps were high 80's and near 90 when I had reached the campsite; had about 1/2 tank of fuel. Left Colorado this past Tuesday with the 1/2 tank of fuel and the temperature was about 45 degrees. When I got home it was 8 hours later 75 degrees and 1/2 tank of fuel left. I filled my MH up when I got about 1/2 tank on the way home which I always try to do. Made home without trouble whatsoever. I had changed the fuel filter about 4 years ago, cut it open and it appeared remarkably clean. This was my first trip, unfortunately, of this year. I keep my fuel tank full during the winter plus putting Sta-Bil in it. I've made this same trip about 5 times in the past during the same time of year. I am no mechanic so do not know how to test many of the prior suggestions in this post. Hate to take it to a mechanic and pay for trouble shooting and not perhaps find anything. Simply baffled, any suggestions or ideas anybody would have I certainly would appreciate it. Thanks.

[GypsyR]

OK, a couple of months ago the trial run of my newly rebuilt transmission was a three hour drive over the Blue Ridge Mountains. (Gatlinburg.) Not real big on test drives, me. All or nothing I guess. Transmission acquitted itself well but the engine was...."sputtering"?....a bit at torque peak RPM's on hard climbs. Without gauges to tell me anything or a datastream from the PCM, it just felt to me like the engine was starving for fuel. Again.

So prior to this weekend's two hour drive into the lower Blue Ridge Mountains "Bryson City) I wanted to see about that. Because I felt like throwing some parts at it, I bought some eBay "uprated" fuel injectors. Rated at 25 pounds over the stock 24 pounds. Piqued my curiosity. Whether or not that added potential of a bit more fuel counts for anything I cannot say. But they are new, clean, and they work. Cheap enough to where I was feeling a bit iffy about them. But...https://www.ebay.com/itm/294809566795

But the big thing was an adjustable fuel regulator and a permanently mounted fuel pressure gauge to track it. After the test type fuel pressure check gauge loosened at the fitting and leaked I kind of soured on driving around with that hooked up.

So the regulator has a handy port on the side of where the sensor for the gauge goes. Got all that installed and set the pressure a few pounds above the stock 39-40 psi max. Without actually test driving it, again. Got a deal on the gauge setup as it was sold as "for" a Mitsubishi Starion. Who has one of THOSE anymore. I had a gut feeling I could make it work on a Ford and took a shot. It did. Apparently it was just a standard setup but with an added threaded adapter I could unscrew and toss. Not real big on digital gauges but for the money it works just fine. (eBay, $70)

Had a time figuring out the pressure regulator. First I was told there were "three bolt" regulators and "two bolt" ones. I have a three bolt. Then parts listing were kind of unclear on exactly which one I needed. While they sell a buttload of them to Mustang guys with smaller engines, the high performance 460 market apparently isn't too big. I gave up on relied on a couple of Mustang guys who assured me what I wanted was an Accufab regulator "for" a 1990 Mustang 5.0 and it would work. $150 and evidently they did not steer me wrong.

But a week before leaving out I decided I just couldn't go without having a look at my in tank filter. Again. Also I had lost a little faith in my made in USA pump. Came within a hair of ordering that Walbro pump I wanted but didn't. Dropped the tank, half full this time, didn't bother to drain it. No excessive dooky in it this time that I could see. Filters caught a little bit more stuff but nothing like even approaching enough to restrict their upgraded capacity. So now I'd really lost faith in my pump. But it was too late to get another one delivered in time. So I put it all back together. Getting pretty good at it these days. I didn't get home from work to start on it until 6:30 PM and had it back together and running by dusk.

Acid test. Test drive? What test drive? Filled up the tank with gas, coach with wife and three grandkids, and off we went. Coach ran its best yet. Non-mechanical wife noted that though it still worked hard on hills, it no longer felt like it was "struggling". The lean sputter at torque peak was definitely gone. (I guess it was a lean sputter then.) Fuel pressure seemed too high to me, peaking at 46 psi at times. I was a little worried about the injectors with higher pressure and also wondering how my fuel mileage was suffering. But I made the identical trip right at a year ago and remember the generator ran out of fuel at 1/4 tank on I-26. About 20 miles from home. This year at the spot I had 3/8 of a tank and the generator ran all the way in. So not only was mileage apparently not worse, it may have improved. Only one comparison though and I didn't measure it. I keep meaning to figure out exact fuel mileage but never do.

I did sometimes get a "lean pop" through the intake when it was cold and/or at sudden acceleration from rolling at low RPM's before. That seems to have gone. In its place now at like 10% throttle just rolling I have an occasional surging of RPM's. Since the former is noticeable to passengers where the latter is not, then that's a plus. I can hit the throttle or drop throttle and lose the surge, so a minor annoyance. Still it's there and could be better.

Faith renewed in the fuel pump and filters. Pressure requested provided just fine. Maybe I can leave the tank on for a while.

Another trip in a few weeks and then two more behind that so I don't want to get to deep. But I am rubbing my hands over putting some headers and a different exhaust on. But not the bolt-on headers which I think to be overpriced. Since they are very close to the much cheaper 460 headers sold for 1970's or 1980's pickup trucks I am going to take a shot at fitting some of those. I don't see why they can't be made to work so I am going to throw down a few hundred bucks and take a shot. There's a fair chance I could be wrong and it will take an act of God to make them fit so I am putting that project off until winter so I won't be too pushed to get it done and the coach back road ready too soon.

Forgot. I didn't get it done but once I drill a hole and weld a bung on the exhaust I will be able to put a wideband O2 gauge next to the pressure gauge on the dash. Then I will finally be able to freaking SEE what the fuel ratios are and see about tweaking things. Maybe knock the surge thing out. Not sure if I'll get that done by the next trip but I will dial back my fuel pressure a bit. I think I'd be happier with a peak of maybe 42 psi.

[MarvinG]

Thanks for the update. Very interesting! I’ll be very interested to hear how your next “test” drive goes at the slightly reduced pressure.

[techguy22]

Gypsy, did you replace the injectors and regulator all at the same time or did you do the injectors first and then the regulator? I wasn't clear from your post. I'm wondering if you got better mileage from having clean injectors? The PCM should compensate for the higher injector volume by just reducing pulse-width. However, having the increased volume would allow the computer to provide more fuel at WOT.

Also, have you checked your TPS? It could be happenstance that an unrelated issue came up and the TPS would be a possible cause of the surging in that throttle range. The generally wear out where you move the pedal back and forth the most.

I'm happy to say that my "canless" fuel pump upgrade has been performing flawlessly on my coach. I'm curious about your injectors because I've been thinking mine could use cleaning or replacement after 30 years of being around and that price is really reasonable.

[GypsyR]

It might be theoretically possible to replace the fuel regulator without at least partially removing the fuel rail but that's a bigger challenge than I am up for. It was tricky as it was. I didn't remove the upper intake and removed as few other things as possible to get in there. Since what I did was the same way I pulled it to get the injectors out for cleaning last time it made sense to me to go ahead and swap them in too.

Changing multiple variables at the same time very much violates the rules of the scientific method way of troubleshooting, I know. But I'm consciously kind of winging it. If I were deep into scientific process (off work) then I'd have some idea of what my actual fuel mileage was, right? Plus my time is limited. My wife has a commuter car and a kid hauler SUV. I have...two trucks, three Mustangs (all in "project" stage), a broken "let the kids borrow" mini van, another car I need to get rid of, and five motorcycles. newest of which is a 1993. So with all that plus the calls of semi-rural living my attention is pretty divided.

Since my injectors cost less for a set than a single OEM replacement I was pretty wary and actually halfway expected to have a dead one or two out of the box. Not so. After I had it running I put an ignition scope on it and the firing lines all indicated nice and consistent fuel burn lines. I was very pleased.

Anyway the computer does try to match fuel flow to what the O2 sensor, TPS, etc tell it. THat all goes out the window at full throttle though. I'm told the stock ECU maps it uses at full throttle tend to be a bit on the lean side. So the extra fuel flow was to come in then and apparently it worked. Speaking of the TPS, mine is overadjusted as detailed by member "Househusband" somewhere in this forum section. The idea being tweaking it to delay upshifts on hills. It's Ok but I'm thinking of putting it back stock so I can kick down in anticipation of hills better. Another part of the tweak was diddling the EGR valve setting to fool the ECM a little about its functionality. I think I will leave that part be.

I've never been terribly impressed by ultrasonic bath cleaners but they are reasonably priced these days. But in my opinion they are a waste on injectors unless you use a pulse width generator to cycle the injector at the same time it is soaking. I have neither of those tools and little interest in buying either. Not because I am cheap, I can prove I have more money invested in tools and automotive repair type equipment than I do my house but I've gotten to where I feel like drawing a line. I can't own ALL the tools, I have nowhere to keep much more. And with apparently quite good injectors being sold this cheap.... Anyway old Ford injectors have little screen in the top. You can spray them out with regular carburetor cleaner and you've done 75% of the cleaning right there.

I have my doubts about any gains due to extra capacity rating. All through this thread I have been about making sure the engine is getting enough fuel. Same thing with the injectors, I basically wanted to be very sure they were not a restriction. Once I put headers on then will I feel I am actually moving beyond stock power.

Lunch over, back to work.

[GypsyR]

Busy doing all kinds of other stuff but we have a small trip coming up after Easter and I got out there to shake the winter off the system. Nice and warm so I could run the AC's. Generator fired up and ran them happily. Water running from the tank being filled. Trying to be prepared for weather and such during winter. I filled the fuel tank last fall.

Engine won't start. Glad I left the fuel pump ammeter on the dash as it shows there is power to it, it's just not using any and running. Blast. Like 450 pounds of fuel in that tank. Preliminary inspection shows no obvious damage from critters chewing wires. Fuel pump relay is working. Smacked the fuel tank to see if the pump might be "stuck" and needing jarred loose. No dice.

So here shortly I guess the tank will be coming down AGAIN. Think first I might just order in that Walbro pump that I had wanted way back in the first place. Whether or not it is actually a pump failure it will make me happier to have it.

[MarvinG]

Oh man, my heart sinks to hear that. I remember the failure of my first replacement pump. I changed it along the side of the Interstate on ramp. Since I had gone in from the top, I dumped all my fresh water, then changed it out to the original but questionable pump. I was thankful i had brought it along for the ride. Probably took an hour to an hour and a half. I sure was glad to hear that engine come back to life.

[techguy22]

I was sad to read this... what a bummer. I also keep my tank full for the winter as these days you never know how much fuel will cost the next season.

You could pump most of the tank out using the generator feed tube and at least get it easier to pull down. Not sure where you would put all of that fuel though unless you started being your own gas station for your vehicles.

I'm happy to say that my re-engineered setup has been working flawlessly... however I haven't fired up my rig for the season yet this year.

[GypsyR]

I'm taking it as "it's always something". My biggest issue on top of working fulltime is that I'm neck deep in a complete bathroom remodel, down to stripping the entire floor out. While she isn't tapping here foot yet...

Motorcycle jack I've been using is rated for 1500 pounds. I figure my full tank is around 480 pounds so thinking of trying it. One time I pumped the fuel out. I have four 5 gallon cans and my pickup has dual tanks that hold 33 gallons. So that helped. Last time I dropped it I think it was below a quarter tank. My pump is a bit slow though and I'm pressed for time to work on it. I have some time before I want to be using it though. Thinking on it.

[GypsyR]

But I ordered the pump I originally wanted anyway. Directly from Walbrofuelpumps.com. No counterfeits for me! it maybe some other problem and I won't need it but I'm putting in anyway if the tank comes down.

[GypsyR]

Checking on my pump order, it vanished. Not shipped, not charged for it, just like it never happened. No Walbro for me, not in time anyway. Fall back and punt time.

Dropped tank. I was going to drop it full but fuel was slopping out the filler when I started to take the hose off the tank. Got a long section of 3/8" fuel line and hooked up my handy pump setup on a Milwaukee cordless drill. I have one "see through" 5 gallon gas can and by timing swapping it back and forth it was easy to monitor when it was nearing full and dumping that into the other containers. Skimmed off 20 gallons with the 5.0 drill battery running non-stop the whole time with a zip tie on the trigger.

I highly recommend you drain a LOT more fuel than that. The tank shifted on the jack a bit coming down and OMG is that thing heavy to wiggle back into position. With a LONG pry bar. Down OK and exactly the same as an earlier picture in post #55.

Test light showed power at the plug when DW cycled the switch for me. Hmmm. Pulled the pump assembly. Out and jumped off to a straight 12 volts it ran. This isn't a trustworthy test though as "sticking" pumps can start working if bumped sometimes and I definitely bumped it a bit coming out.

Next I hung the pump on top of the tank and plugged it in. Forced DW at gunpoint back to ignition key turning duty. No pump. Positive power reading on test light. Ground? Banged pump a little and next key cycle it worked. Iffy pump. Whether or not it works is now immaterial, it has just proven itself untrustworthy.

The parts stores sell a Delphi pump which fits. One I used before didn't play well but I suspect filter clogging was also to blame so I'm giving Delphi another shot instead of playing order roulette with Walbro. (Right now) Got one. In the course of swapping it the tiny plug going directly to the old plug cracked when I pulled it off. On closer inspection the pins in it were corroded, one black. Lassoing DW into ignition duty one last time I was able to find that I could press and wiggle this connector and make power come and go. Blast. Multiple issues, again! Quick Google and no one sells a replacement "wiring pigtail" for this as far as I could tell.


After kicking some stuff around I decided to void the heck out of my warranty. I carefully cut the plastic around the plug on the pump until I just had two pins sticking out. One of the earlier pumps had a nice GM style removable plug with it as part of a kit. I trimmed off two wires and soldered them to the pump pins. No faith in wires hanging off just by solder, I laid a bit of epoxy on around them for support. Then the plug wouldn't fit through the gap in the plastic pump housing so I had to take it back apart and grind a bit of plastic off the plug. Then with a bit of force it popped through.


Assembled and plugged in I plopped it back down into the tank. Fired up. Runs fine, sitting still anyway. Fuel pressure on the money. Only downer is that the earlier pump was drawing 3.6+ amps under load where this one is drawing only 2.61 at max. Hmmm. I think last time I ran a Delphi pump I got the same readings. Maybe nature of the beast? Anyway I'm going to run it. Next trip doesn't involve any mountains and is actually not terribly far from home. Within towing distance is I need my buddy to come get us like he did when the transmission died.

On the dummy side. While in the engine compartment I decided to check my vacuum. The gauge has been reading low up mountains as expected but nit coming back up much at all at idle. Worrying me some even though it seemed to be running fine. Dragged out my vacuum test gauge. So old I had to polish the face to see the numbers. Put it on while idling. Low, like the dash gauge. Oh crap. Bumped it moving it around and it jumped up a bit. What? Thumped it with my fingers, a lot, and it finally settled on like 16. Where it should be. And dropped when I revved the throttle to stick again. Hmmm. Reached up and gave the dash gauge a thump. Ding! 16, just like the other one. So of a....all this time! Anyway TWO new gauges are now on my shopping list. Bright side is there is no terrible timing/vacuum issue like I thought the gauge was indicating. I still feel dumb for not being old school and tapping the gauge a long time ago.