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MaxACL
03-16-2008, 08:46
Three times there has been a 1093 code set, the Auto Zone guy said it was a “I’m starving for fuel” code. I had filled with 100 gallons of Biodiesel in Georgia and afterward the attendant said it was made from chicken fat. Still good but had fatty deposits formed at 40 degrees F. So I transferred about 5 gallons of “chicken fat” to 25 gallons of petro diesel. That’s about 5 to 30 ratio or 1 to 6 which is … let me see… carry the one… 16% or B16.

At some point later I could feel a “miss” so I changed all three fuel filters, problem solved. Then last week the first 1093 code appeared, I had it cleared, it came back so I ran straight petro. The big tank in the bed quit pumping altogether, I changes that filter, problem still there (it’s in the 30s and 40s outside right now (NW WA State). In SoCal it seemed to flow so I eased a little into the main tank.. no problem. While in BC I mixed one half gallon of Howe’s cleaner in the big tank with the remaining 30 gallons of (by this time) B5 or B2. Now the little electric lift pump has everything flowing, the SES light extinguished on it’s own but I have a fuel leak in the valley that dribbles onto the ground. Not much, but still there’s a leak. The GM Goodwrench mech (my transfer case went south…again) said the injector pump is about to go.

I have almost 300,000 miles on the engine so perhaps it’s time for a pump. They are about $1,000 from GM. Would a rebuilt pump be worth it? Would there still be any residual sludge in the fuel system that needs purging and how would I clean it out?

It’s an ’02, with a ZF6, CA emissions and no mods.

I drive about 10 to 12,000 miles/mo and need something dependable.

By the way, 300K miles on the original brakes, front end parts and the spare’s never been out of the cradle. The General does a few things right

Mike

Duramaster
03-16-2008, 13:45
I don't know how to respond to your sludge complaint, BUT the fuel leak from the pump needs to be addressed RIGHT AWAY!!! Is it the pump? If you look down in the valley of the engine near the pump, is that where the fuel is coming from? The reason why I ask is at my shop, we have had a few 2006 LLY's come in with detonated pumps. Put a new pump in and things are ok for awhile............. Next thing you know the truck comes back with misfire DTC's and no power. We (dealer techs) are being instructed to replace the INJECTION PUMP, BOTH FUEL RAILS, ALL INJECTORS, FILTER HEAD and TRANSFER PUMP. We are also supposed to flush the entire fuel system to get rid of any metal particles in the fuel system. I guess what is happening is that there is some sort of ceramic pellet in the pump that is deteriorating that starts causing all sorts of issues in the pump. I just looked for a bulletin on this, but I cannot locate it right now. I don't know if it pertains to your truck (2003), but I know that it covers the 2006. I am in the middle of repairing one right now (2006 GMC C-4500). Good luck with the sludge................ :o

DmaxMaverick
03-16-2008, 14:29
It could be the pump, but on the LB7, I'd suspect the FPR, first. It would explain the leak, and inability to build pressure. It is replaceable alone, not needing a new pump. The sludge/grime is likely external, a result of the fuel collecting dirt after the leak. Cross your fingers!

2500HDTalley
03-16-2008, 22:45
I had the same problem with my 02 - LB7. The problem on mine was the fuel injector pump. Replaced it, leaks went away and fuel pressure went back to normal.

Kennedy
03-17-2008, 12:00
Clean the tanks and fuel system, filters, etc and put only petro diesel in the tank. Then measure restriction when the issue crops up. If the restriction is within reason, THEN it's probably time for a pump.

Bio etc can be a major pain in the ass...