"02" 3500hd fuel pump location

[welder1965]

I am having problems with my duramax 6.6l turbo just shuting down and was told that it was probably the fuel pump. Can anyone tell me the location of the fuel pump, i was told it was in the tank and after buying a 350.00 "fuel pump" i found out it was only a sending unit. i followed the lines from the tank there is no fuel pump on the frame rail either?

[DmaxMaverick]

Welcome to the Forums!

Your truck doesn't have a "fuel pump". You've been given bad advice. The only OEM pump is the HP fuel pump. The fuel is suction from the tank to the engine.

Under what conditions does it quit? What do you have to do to make it run again after it quits? Is your SES lamp on? Did you have any DTC's (trouble codes) pulled? This would be very helpful to diagnose your problem.

[welder1965]

Hi, Thanks for the reply. The truck quits with no rime or reason, one time it will drive for a mile another time it won't go ten feet. each time it quits if i prime the filter it normally will start and run again. I ran the codes with an obd 2 scanner the codes the showed were, glow plug malfunction and a mfg code U1800.

[DmaxMaverick]

OK. Now we have something we can work with.

The U1800 code could be the cause of the problem (FICM not responding). Check the FICM fuse and the connector at the FICM. The fault is an open circuit, or there would be other codes present (like U2104, U2106).

The GP circuit code (probably P0380) could be a failed GP controller fuse, bad glow plug(s), or bad GP controller or relay. This code won't cause engine stalling. It will cause the SES and possible hard cold starting in very cold temps.

Priming the filter could be a coincidence, as the PCM will reset and run at default fueling, even if the FICM fails to respond. It sounds like it is intermittent, which is most likely a poor connection somewhere.

If it's a fuel system air leak, read on....

If priming the filter gets it going again, you most likely have an air leak. If the engine only stalls when started cold, the air leak will be small. Stalling while normal driving indicates a large leak. Was the filter replaced lately? If so, remove and reseat it. If not, replace it (cheap insurance, anyway). Use some grease or heavy lube on the O-ring. Make sure the drain fitting at the bottom is well seated and use some grease there too. Make sure the drain valve is also well seated. It doesn't have to be too tight, it's sealed with an O-ring. Check your system for signs of fuel leakage. If you see any spots wet with fuel, that will likely be the location of the air leak. The fuel cap can also be part of the problem. If it doesn't vent properly, it can cause significant fuel tank and system vacuum, which will exploit any air leak possibility. You can try leaving it loose, or just replace it. They're not that expensive, just make sure you get one for Diesel (they vent differently than the gassers).

The fuel filter assy has been known to fail and leak, but try all the easy stuff first. Unless you still have an extended warranty in force, the assy will be quite expensive.

[edit]
If you've used a power box, like Edge, remove it. It could be the entire issue, and all bets are off until you eliminate that as a possible cause. Diagnostics will do no good as long as it is in place. If any of the connector pins are not making full contact, it could cause everything you have seen. It not that uncommon.

[welder1965]

I'll give these things a try and will let you know thanks again for your help!:)

[DmaxMaverick]

You're welcome. We'll be here........

[welder1965]

Hi, The filter was changed twice since this started happening no sign of leaks anywhere. we are checking on the FICM problem now. One other thing we were told is that if the key or tumbler is bad that it could cause the stalling due to the VTD system. Is this so? The reason i ask is that someone tried to pick the tumbler and now you have to play with the key to turn it on.

[DmaxMaverick]

The VTD could very well be the cause. It could also be triggering the U1800. The VTD interrupts the communication from the FICM. Before continuing your diagnosis, you need to eliminate it. Pumping the primer will not help if it's a VTD, but the time it takes to pump could be enough for the switch make contact, or time-out the VTD (20 minutes, IIRC on the 2002). Pumping the primer could be a coincidence.