2003 Duramax LB7 problem

85Yota

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Ok so I have a 2003 Chevy 2500HD Duramax. 160k miles had new injectors done at 140k miles by previous owners. It has hp tuners tune s&b intake and stock besides that. Needless to say was out in Pahrump NV 180 miles from home towing home another bronco I'm parting out. Went to circle k fuel station a filled it up it started and I pulled forward about 6 ft and truck died. Cranked and wouldn't start. Bled the fuel filter and pumped that up and that went well but still wouldn't start. Did that 3 times and wouldn't start. So I waited for many hours to get towed home, had a friend's dad tow my trailer to his home that I'll get later. My 3 hours of googling when waiting to get towed it seems the fuel filter housing is a common problem. Gonna change fuel filter and see if that fixes anything but does anyone know Duramax and have other things for me to check and/or a replacement fuel filter housing that's better than stock which I've read is prone to fail and need to be rebuilt or replaced. I'm needing to get the truck back running and I want it to be reliable to not have to worry about this happening again in the future since I tow fairly often 6+ hrs from home.
 
I have an LLY that did the same thing. Pumped up the filter head and it took FOREVER for the truck to start. I have plans to rebuild my filter head and then start moving down the line from there... I also had an LBZ that would go into reduced power on low rail pressure and it ended up being a problem with the sending unit. Once the truck got below 1/4 tank it would start sucking air from there.

I’d definitely start by rebuilding the filter head, the kits are cheap and it’s an easy job especially if you’re already planning on changing the filter. But the best thing you can do with any older Duramax is a CAT spin on fuel filter upgrade and a lift pump. I ran the Fleece in tank lift pump in my LBZ and I LOVED it. No bulky pump hanging off the frame and it was nice and quiet.

Know anyone with a good scan tool? Knowing rail pressure while cranking would be handy amongst other things...
 
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I don't know anyone with a scan tool. I'll do the filter head and hope for the best. Seems like an easy fix if that's all it is. Tank is completely full now and was over half tank when I filled up so I could make my drive home. Hopefully it's a easy fix with filter housing for now. Than I'll look into a lift pump and upgrades in the near future. Need to get this thing going so I can drive back out to get my trailer with a 83 bronco on it back home.
 
Could be worn o rings on the primer pump not allowing the truck to keep prime you can get a rebuild kit from Napa for like $20. I did it for a lbz that had a similar issue after that’s he hasent has a issue
 
Ok gonna get a rebuild kit and should be able to tackle that tomorrow or if not in stock Wednesday. Just need to get this truck running good so I have a truck again.
 
Well my truck just did the same thing (2004 LLY). Got home from the lake, shut the truck off for about 20 minutes, came back out and fired it up only to move about 20 ft before it died. Primed the filter head (had air in it), cranked on it, primed it again (more air), and continued cranking periodically for the next 20 minutes as not to overheat the starter before it fired back up. Once again below 1/4 tank so I’m sure mine is the sending unit.
 
So are you just going to keep the fuel level above half tank or what's the plan to keep from happening on yours in the future?
 
So are you just going to keep the fuel level above half tank or what's the plan to keep from happening on yours in the future?
I’ve had a filter head rebuild kit in the glove box since I’ve bought the truck, I’ll probably do that real quick one of these nights I’m slow at work this month. Then just to be sure I’ll put a piece of clear tubing in line before the filter head with the tank full and watch for air coming through the line, then again below 1/4 tank to see if I’m still getting air (it was obvious on my LBZ I used to have even sitting there holding the idle high). If that’s the case I’ll do a Fleece in tank lift pump.
 
Filter head is most common especially if its still original. Did you loosen the bleeder screw when you pumped it up?
 
Only update is my truck has a bunch of solenoid things above filter housing making changing it a pain. Also I didn't install fuel lines first and they won't reach now. So gonna uninstall it and put those in and then reinstall it. Anyone know if I can move the electrical solenoids or why they are on my truck there when everything online doesn't show them?

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Okay just removed it. Installed the fuel lines. Been trying to get the filter housing bolted back onto engine bracket and the fuel lines just aren't long enough. They measure out a half inch. Can I get just some regular half inch fuel line from AutoZone to replace these or what should I do?
 
Okay just removed it. Installed the fuel lines. Been trying to get the filter housing bolted back onto engine bracket and the fuel lines just aren't long enough. They measure out a half inch. Can I get just some regular half inch fuel line from AutoZone to replace these or what should I do?
Regular 1/2” fuel line will work.

You have all that extra BS because California🙃 don’t mismatch any of those vacuum lines or you’ll have problems.
 
Okay just got some half in fuel line. Didn't disconnect or remove any of the vacuum lines or solenoids. Just got to get the old fuel lines out and new fuel lines routed in and make them a little longer. Feel better about replacing the fuel line since the other ones are 20 years old and have a lot of smaller cracks from heat and age
 
Alright got it All put back together and it's running good now. The line that goes into the filter housing had a molded bend and was tight under everything so I left that piece at the engine and cut use a half inch. Barb coupler hose clamps and a new end to extend it. Replace the shorter one into the engine with a new piece with proper hose clamps, not the factory spring clamp style.

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So got it all together and the cheap fuel filter housing is weeping fuel around one of the steel fittings. I could tell something was loosing pressure since if it sits for more than an hour it takes longer to start than normal. Going to swap this one out for the factory one I rebuilt and keep it as a spare along with fuel line so I can install it easily if needed on side of the road if it breaks down again.
 
So got it all together and the cheap fuel filter housing is weeping fuel around one of the steel fittings. I could tell something was loosing pressure since if it sits for more than an hour it takes longer to start than normal. Going to swap this one out for the factory one I rebuilt and keep it as a spare along with fuel line so I can install it easily if needed on side of the road if it breaks down again.
Dorman filter head I'm assuming? Gotta love aftermarket replacement parts!
 
No it was a cheap one of Amazon. Henkyo or something like that. Was like $80 it's a pain to swap so I ordered a Racor filter housing since they made them for GM and keep my rebuilt one as my spare.
 
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