LB7 Duramax fuel issue.

[Jeep_Comanche17]

Hello I have a 2002 GMC Sierra 2500HD SLE crew cab long bed 4X4. It has the 6.6L LB7 Duramax Diesel engine and the Allison 5 speed transmission. Recently i have had an issue with the truck taking a long time to start. especially when I don't plug in the block heater. When I purge the fuel system (push the primer button on top of the fuel filter housing a few times) that seems to help. I am familiar with the issue that since the Duramax engines pull fuel to the engine with the pump on the engine VS. push it to the engine with a pump in the fuel tank, they tend to blow O-rings on the filter housing. There is a Bleeder screw on top of the housing by the primer button, ive been told these loose there seals easily due to the fact they are made of plastic. aluminum ones are $10, I plan on replacing it. The injectors were replaced with aftermarket Bosch injectors to fix the common LB7 injector issue by the previous owner so I don't believe that's the issue. Also does anyone know the part number for a cat fuel filter that will fit? Thanks, Jim

[Colossus]

Glow plugs get lazy and tired after awhile as well, suggest you consider replacing those.

[jake111]

If you still have the original filter head/primer, then you should consider rebuilding it (about $20), or better yet replacing with a whole new assembly. With a little searching, I found a Parker-Racor PFF4245R2-04 filter head replacement for $120 and it should be the one for your LB7, AND it comes with a new Racor PFF50216 filter AND with a new water-in-fuel sensor!!).

 

You should research filters. CAT makes good filters, but I haven't heard of one that fits the stock filter mount. Search more and I think you'll find the Racor PFF50216 is the BEST filter for the Duramax (all years). AC Delco upgraded a few years ago and was using a rebranded Racor for awhile, but I'm not sure of that now (and they would cost more anyway even if they were).

 

Of course, glow plugs could also be a problem...

[Jeep_Comanche17]

colossus jake111 glow plugs were replaced by previous owner, maybe 30k miles ago. i guess depending on how much they were used the could be burnt out. dont really want to take them out cuz if the mushroomed out that will screw up a lot of stuff. also got the aluminum bleeder screw for the fuel filter housing and plan on installing soon to see if that will help. pretty sure the plastic one on it is cracked. as for the fuel filter i really want caterpillar as my cousins 03 LB7 had one and it works amazing for him. but i cant find just a filter for the stock housing, only conversion kits. and what are the best bang for your buck tuners out there? dont want something race truck, but towing, fuel economy, and maybe able to roll some coal would be nice