This one has me stumped. I'm still thinking the fuel pump is no good, but I could be wrong. Fishing for other ideas.

I tried both the fuel pressure test and swapping the horn / fuel pump relay.

The relays swap back and forth and the horn still works. With either relay the fuel pressure stays at zero.

I dropped the fuel tank and removed the fuel pump and tested it. Seemed to work fine. Put the pump back in and tank back on and disconnected the fuel filter on the tank side figuring with key on it should pump fuel out. Maybe the filter was plugged. Nothing.

I'm tempted to go ahead and get a new pump, but if the problem is elsewhere that will be $105-$185 spent for nothing.

Any ideas?

 

Sounds to me like a fuel pump as you said.

 

how did you test it out of the tank? could it maybe be a bad ground when installed?

 

Horn relay and fuel is the same? When mine went out I swapped the tow relay.

If it's not the fuse? And not the relay? And you havnet hit anything then I would say fuel pump. You should be able to hear it whinning from under the truck or from the filler tube.

 

I removed the pump from the sending unit - preparing to replace it - and figured I'd run 12 volts to the leads to check for sure. It worked just fine.

The truck ran fine. 235,000 miles plus on all factory equipment. Even the battery is still original. I picked the truck up at an auction yard of all places, but since I managed the yard there I was first to inspect it at the gate. Belonged to a construction Co. used as a Supervisor truck and was serviced regularly from day one. I put the piles of service slips from the glove box in a folder and everyone afterwards that looked at the truck saw 203,000 miles on a 4.6L V8 and they'd seen enough.

Needless to say, the truck has never had any major problem until now. Luckily it decided to quit in the garage and not start instead of some untold miles away stuck in a parking lot or something.

Ran fine every day and then one morning, nothing. A couple sputters like it was going to start, but that was about it. No fuel.

 

Yea, I'm not 100% sure, but a How-To I checked said that #19 in the under-hood fuse box was the fuel pump, but mine doesn't have #19, it goes from #18 to #302 or something, not a fuse but a relay . . . and another matching relay that seemed to be where the horn [fuse] should have been.

I may have to research the whole fuse panel layout again under the hood.

It hasn't made a sound yet while plugged in or installed. I tried it just plugged in before putting the tank back on but figured it may have needed a ground. After reinstalling the tank it's pretty obvious the tanks are insulated from any metal-to-metal contact. Just plugged in it should have worked.

 

My book says "fuse/relay Locationg #10 20A" That is the box under the hood. And the relay is 301.
On mine I traded with relay 302, that is the power wire in your trailer plug. And then tested the power at the plug.

 

Good to know. I checked the fuse box again and found #19 at the bottom but it's fine. All the fuses are fine since i checked them all.

Something I noticed on a sticker plain as day under the hood is that the truck has a fuel pump shut-off switch hidden somewhere, and without a manual I'll have to go digging to figure out where it may be hidden.

I believe they are usually on the passenger side under the dash side wall, but I didn't see anything there at first glance.

I did have a little trouble with the cheesy battery connector (+ positive side) and lost battery connection a few times in the past. Maybe that caused the switch to flip . . . ?

 

Yah that is on the passenger side kicker,little box with a button on top that you push down. But I really think you gotta crash for that to trip.

 

Yup.

Nothing to reset. Everything checks out.

Guess I'll just have to get a new pump and hope like crazy that that's the real problem.

Only have to drop the tank again . . .