My first time posting here but have been reading most of the evening and haven't found anyone with my specific problem. 1997 F-250 HD 5.8L 2wd. Recently purchased from my employer and the truck had sat around for at least a couple years. I installed a new mid ship fuel pump and the truck started and runs surprisingly well for how long it has sat. (fuel tank was gross and the fuel pump had broken wires so i drained the tank and replaced it) I filled the tank with fuel and went on a test drive Saturday. I made it 23 miles And everything was going great. At the 23 mile mark I am 6 miles up a 9 mile 6% hill, and I got slowed down behind another car, I moved into he fast lane and tried to get it into passing gear to pick up speed and the truck fell on its face. Had zero power and was bucking and jumping like it was almost running out of fuel but would then pick it up again. I immediately said well I'm an idiot and didn't change the fuel filter and it is clogged now. So by cycling the key and restarting the truck every time i needed fuel pressure i got to the top of the hill turned around and to the parts store. Changed the fuel filter in the parking lot but didn't make it a mile before the problem came back. Still 16 miles form home i limped it along cycling the key and restarting all the way home.
This morning I crawled under the truck and pulled the pump (flatbed so I don't have to drop the tank) And the strainer is totally brown with rust and debris so I go grab another pump and install it thinking the crap in the tank destroyed the ebay pump i put in (I needed a new hanger and the parts stores didn't have the correct one for the steel mid ship tank) After I installed i went for another drive. This time i made it 7 miles and exactly the same scenario, try to get it into passing gear and it "runs out of fuel" and it is limping back home by cycling the key. When I got home again i thought well maybe I am dropping power to the pump so i pulled the fuel pump relay and ran a hot wire direct to the pump, this time i didn't make it out of the cul de sac before the same behavior starts again.
Being that I work for a Ford dealer in the parts department i still have access to wiring diagrams and from what i can tell the only two things between the relay and the pump are the inertia switch and the tank selector switch. Does it make any sense for either of these to be failing by going into passing gear? 13.5v to the pump should always be the same.
Could the PCM be causing this even though the fuel pumps aren't run by the PCM? And cycling the key 3 times makes it start every time?

I have used this forum and others like it for years solving problems but this is the first time I have been logically stump about a path forward so I am reaching out. In the future Now that i register I can use some of my dealer resources to help others find parts and diagrams as I read through.

Thanks In advance for any and all Help.

 

Have you tried pulling trouble codes?

This happened about 6 months ago to another user. I believe the culprit was a bad fuel selector switch on the dash. The contacts became green with corrosion and would heat up and cause fuel issues. The switch can be easily taken apart and cleaned. I suggest trying that first since it cost nothing.

Instrument the fuel system with a loan-a-tool fuel pressure gauge and tape it to the front window. That'll tell you for sure if you have a fuel supply issue or something else.


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If you could upload a PDF of the 1992-1996 Ford f series illustrated parts catalog, that would be great.

 

I have not tried pulling codes because I haven't seen any thing on the dash but i always forget OBDI is weird like that. I will try that tomorrow after work. I will also pull the fuel selector switch and see if it needs a cleaning.

Unfortunately I don't have a way of doing a full catalog for a vehicle the software only allows individual pages to be done at a time and there are lots of pages for any given vehicle, If i remember correctly the micro fish for the 77 ford f series is like 1600 pages. The fuel tanks and pumps for a 1997 5.8l truck is 25 pages by itself. The new stuff is way more than that. I you have something specific just ask and i can send that page no problem.

 

You “drained the tank and replaced it” so only replaced the fuel delivery module or you also replaced the tank? If you are saying that you also replaced the tank where is the rust coming from? One tank or two?

You ran power directly to the pump so I don’t think you are going down the right path thinking that the power is dropping. I’d be more concerned about all that debris in the fuel system.

 

Fuel pump module was replaced both times, debris is coming from the tank. Looking at the wiring diagrams the fuel tank selector switch could be the culprit.

 

I will ask again. How could the switch be the problem when you said that you ran power directly from the relay to the pump? That would bypass the inertia and tank selector switches.

Stolen wiring diagram from another thread. Red arrow added by me.

 

The way i wired it was to simply force battery power into the 87? terminal of the fuel pump relay, so in theory it would still be going through the inertia switch and selector switch. I am going to put a pressure gauge on it tonight and see what it is saying.

 

I finally got a chance to work on this again. I replaced the fuel tank selector switch because it fell apart when i attempted to unplug the electrical connection. zero change in the running condition of the truck. pulled the vacuum line to the fuel pressure regulator after reading that they fail regularly, sure enough it was spitting fuel. replaced and had zero change to running condition. hooked up fuel pressure tester and at idle it sits at 28 psi when disconnecting the fuel pressure regulator it jumps to 38 psi. With the engine running and contemplating my next move I noticed the fuel pressure dropping and the engine running worse until it died. Once the engine dies it will hold between 8-12 psi for a few mins (haven't observed any longer than that) The last time I caught it dropping pressure i pulled the vacuum line to the regulator to see if pressure would jump, it did not change the rate at which the pressure dropped. I have also switched around relays to make sure it isn't getting hot and dropping contact in the relay again no change. The only thing I can think to do next is put and extra battery on the bed and wire power direct o the fuel pump to see if maybe I have a resistance problem in a wire that when it gets hot the pump no longer gets enough voltage to run and as soon as you shut the truck off it cools enough to provide power again.

Any thought or recommendations for things to experiment with, this is my 3rd vehicle so I'm in no rush to fix it, I'd just like to not spend more money on parts that don't fix the problem.

thanks in advance

 

Pressure is a little low but that could be the gauge. It seems like it is the pump again. Maybe I missed it but did you clean out or replace the tank or only replace the pump the second time? Do what you want but hot wiring the pump to a battery in the bed is a recipe for disaster. How would you shut off the fuel if something went wrong?

 

I only replaced the pump the second time. Tank was cleaned the first time the pump was changed. I have no intention of using the battery in the bed as a long term solution only as a diagnostic tool. Truck has been running now for 20 mins with the pump hotwired with no deviation in pressure. I am going to drive it around the neighborhood after i finish my lunch to see what happens

 

Disconnect the inertia switch and jump the contacts with a paperclip or jumper wire. See if the condition continues.

 

Looks like I'm going to need new tanks. I removed the valve core for the fuel pressure test port and ran a hose into a coffee can, then hot wired the fuel pump and it was good flow for 5-8 seconds and then just started to dribble out and kind of spit a little fuel here and there. which tells me the pump is gone. So I pulled the pump and sure enough the strainer is caked with material. So I ordered 2 tanks and will grab another pump for the front and a fuel filter and try the whole thing again.