Fuel Problem Cummins

[Therealarw]

(06-30-2023 )Rawze Wrote:  You did not mention what type of external fuel filter. Is it a Davco?.

Does it have a 10-micron filter element in it?.

It is dropping BELOW the filter element?... or just dropping near the bottom of it?. it should not drop below the paper element.


Anyone checked to ensure the bowl of the fuel filter housing itself is not leaky?.

One way to check for pick-up line and tank leaks is to pressurize the fuel tanks to 10 psi shop air onto the bleeder tubes, and let it sit for an hour or so. Check if fuel is seeping out somewhere. WHATEVER YOU DO THOUGH!!! if you pressurize the fuel tanks for a test ... NEVER OPEN THE FUEL CAPS WHILE THE TANK IS PRESSURIZED!!!! .. NOT EVEN A FEW PSI!!! .. BECAUSE THEY CAN AND WILL BREAK YOUR HAND OR ARM!!! put a person in the hospital real fast. There is a LOT of force behind those fuel caps even with only a very few psi pressure in the fuel tanks.

Rawze,
It’s actually a Paccar Filter it’s a K37-1004. Which I think is a 10 micron. But the fuel stays about at the bottom of the fuel filter. It’s the only truck in my fleet (20 trucks) where the fuel is at the bottom of the filter. This is with the truck not even running. I’m thinking I have a few leaking injectors because it’s a hard start. Takes 3-4 key cycles just to get it to run and it runs super rough for 5 seconds before idling the right way. Then I noticed the truck will shut off when RPM’s drop down to idle, then I have to cycle the key again to get it running. Unfortunately I can’t test it out right now as I had to drop the main bearings. Most of them had been scarred due to the fuel pump failing

The bowl is fine, it’s pretty new, all the suction lines have been replaced.