[96nightmare]

Been having issues, if you have read my other thread. I now have no fuel pressure, i pulled the cap off of the fuel bowl and cranked, the fuel level did not change. We have replace the fuel pump. Any thoughts

 

[Snowtow]

Switch tanks and try it again. The pickups in the tanks are notorious for falling off due to deterioration.

I haven't read your other thread. It's usually better just to add to one thread if the problem is related.

 

[96nightmare]

Have tried both tanks. At this point I am not sure what is related, other than it is the same truck.
We did even put in another fuel pump just to make sure we didn't get a bad one .

Beginning to fear the worse. That it is done for.

 

[bugman]

You might have one problem and you might have multiple problems. I'd put another 5 gallons of fuel in the tank and see if you can build fuel pressure or get some fuel into the filter housing.

On your other thread when they hooked a scanner up and told you that you had a couple of bad injectors did they look at the IPR duty cycle?

 

[79jasper]

Tank pickups aka shower heads probably broke off sending junk into the fuel lines, so no you have a clog.
Or maybe you have a bad line so it's sucking air.
Or maybe the quick disconnects have bad orings.

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[96nightmare]

Yes he checked the IPR sitting and when it shut down he was checking it on live feed. It checked out.

 

[96nightmare]

Here is what we have done. Disconnected the fuel supply line from the tank selector valve and inserted it in a fuel can. Truck runs great problem solved.... wrong. We then discovered that fuse # 6 controls the tank selector valve and the ac clutch, fuse is blown, problem solved ... wrong. put in new fuse and it blows, unplug the tank selector valve and fuse holds. so we plugged the selector valve back in and unplugged the tank switch in the dash... fuse holds. So if either end is unplugged fuse holds if both are plugged in the fuse will not. Has anyone had this problem and what was the fix. Dash switch not to expensive, tank control valve over 400.00.

HELP

 

[madpogue]

Diagram - http://userpages.chorus.net/elephant/FuelTankSelector.pdf - use this to check voltages where expected, test wires between switch and valve, etc.

My first guess would be that the valve is stuck between positions, and when you try to energize it either way (and the switch always energizes it with one polarity or the other whenever the key is on - see diagram), it draws too much current trying to move, and blows the fuse. If everything checks out electrically, I would remove the valve and blow in the various ports and check to see which ports are open to which other ports. Then I'd try triggering it with a test battery, switching polarity both ways. Be ready to pull one of the test wires quick if you wire it directly with no fuse.

 

[96nightmare]

One more bit of info, the fuel gauge is pegged to past full no matter which tank is selected.

 

[madpogue]

That ^^^^^ indicates a break (infinite resistance) in the circuit between each tank sending unit and the gauge head. But once again, speculating here, if the selector is physically halfway between front and rear, then the contact that connects either the front or rear sending unit and the gauge head (see terminals 4,5 and 6 on the selector connector) could be in a position where it's not connecting either one. That would mean an open circuit, infinite resistance, and indeed a gauge pegged past full.

 

[96nightmare]

Turned out to be the Tank Selector valve.

thanks for the help