stalls and wont run when hot.

[srs1983]

Hi im new here and just joined i have a 93 gmc k1500 6.2 diesel that ive been working on for awhile now anyone who may be able to help me i greatly appreciate it ive checked everything i can think of ive had the ip rebuilt, new lift pump,and oil pressure switch and fuel filter the truck will run good til it gets to operating temperature then stalls and has trouble restarting once again any advice is appreciated.

[john8662]

Sounds like some parts have been changed. When running, is the fuel pump actually running? You can feel it pulsating when it's running if the OPS is providing power and the pump is good.

Fuel cap can cause stalling as well. Check for pressure in the fuel tank. For testing just loosen the cap to where it can't seal and test.

Other than that it's possible you've got a restricted fuel return line on the injection pump. Check the hose that comes out of the IP for kinks.

A restricted return system will cause stalling too.

J

[srs1983]

thank you for the help I put a new cap on it yesterday and I pressurized the tank to check for leaks and my lift pump is definitely pumping however i will check for restrictions in the return system I have not done that yet.

[arveetek]

I had an issue on my '95 that caused me to nearly pull my hair out trying to find the problem: it would start and run great, but after a few miles, it would stall and shut down. When I would pull over, the fuel filter housing would be empty as if there was no fuel, but the lift pump would be running. Letting it sit for a while would allow fuel to start flowing again.

Long story short is that the "sock" in the fuel tank was plugging up and squeezing down under suction from the lift pump, causing fuel flow to cease. Letting it sit would allow the "sock" to relax, and then fuel would start flowing again for a while.

Putting an OEM "sock" back in the tank cured those issues.

Casey

[srs1983]

thanks im getting ready to check the tank now i have done everything else i can think of.

[srs1983]

thanks everyone for the help i pulled the tank replaced the sending unit and sock and that fixed my problem.

[Dvldog8793]

As stated earlier...
Make sure the sock is of the Delco variety. It should be fairly stiff with one end round and the other pinched and a metal press on fitting.
The aftermarket parts are NOT GOOD....

[Big Ray]

I'm thinking of removing the sock completely and running a pre-filter before my new external Walbro lift pump.

Thoughts?

[DmaxMaverick]

I'm thinking of removing the sock completely and running a pre-filter before my new external Walbro lift pump.

Thoughts?

The (correct/clean) sock is necessary. If for any reason it plugs up, you have bigger problems. It not only "strains" the fuel as it's picked up, it also diffuses and reduces the inlet velocity of the fuel, making it MUCH less likely to pick anything but fuel. With just a "pipe" in there, some wise-azz kid could have you scratching your head for weeks (after he drops in a marble, or a wad of bubble gum). Even if that never happens, a bare pipe will cause are to suck in at around 1/2-1/4 tank, especially with the fuel pump you chose. Although there's nothing wrong with filtering the fuel at the lift pump inlet, in any case.