I bought a 1997 F350 crew cab dually about a year ago. I have been lurking here ever since, learning interesting and cool information, but now I have a problem and am hoping for some help.

As stated it is a 97, completely original except for a K&N air filter, with 152K miles. When I got the vehicle it already had an issue with the switching valve system that I have never chased down. Basically it only runs off of the rear tank, moving the switch does nothing. No matter the switch position It continues to pull from the rear tank, and the fuel level gauge never changes. Up to this point, I have just ignored that issue and run exclusively the rear tank.

We also learned after a week or so of ownership that the rear tank has a cracked pickup and runs out of fuel at about 1/4 on the gauge. Ask me how we figured that out.....

All has gone well until 2 nights ago when the truck started losing power and shut off after a couple of minutes on my wife. She is a well-above average mechanical person, and her instinct told her it was a fuel problem. We keep a 5 gallon jug in the back due to the tank pickup issue, so she poured the 5 gallons in. She them cranked on it off and on until eventually it started. She got about a mile and it did it again. It never started again so we had it towed to my house.

The first thing I did, after verifying a tach signal and oil level, is pull the fuel filter out. The bowl was only about 1/3 full of clean fuel. So I had her crank the engine, and it slowly filled the bowl back up. I put the filter back on it, and it quickly cranked up after maybe 5 seconds. It ran rough for maybe 10 seconds, then idled smoothly for at least 15 minutes. So I took it for a drive around the neighborhood, and at first it ran OK, but I could immediately tell it was down on power. I drove it about 1-1.5 miles, and it started running out of fuel again. It ran progressively rougher, then shut off after maybe 30 seconds and I coasted back into my driveway.

So I again pulled off the filter, and found the same fuel level. I had her crank it again, and this time it pumped some air bubbles and a bit of fuel into the bowl, up to about half full, then quit pumping fuel at all. I filled the bowl from a can, put the filter back on, and it cranked up and ran roughly, smoothing out eventually after pushing all the air out of the system. So I shut it off at that point.

By all this I now know the issue is somewhere from the tank pickup to the actual delivery of the fuel into the bowl. But where to start? That is where I am looking for help. Given this set of conditions, what do some of you more experienced 7.3 guys suspect might be the issue, and where should I look first?

 

I would check the fuel pressure at the schrader valve while it is running. Any chance the fuel pump may be leaking some into the valley?

 

With a broken shower head I guarantee you those plastic bits are in the fuel line and it might be causing your fuel switch valve to get stuck. Blow pressurized air back to the tank and see if that helps, if it does remove tank and clean it really good.