I have a truck at work that we can not figure out and I thought that you guys would know much more than we would. Its a 04 1/2 LLY 3500 reg cab. It has no power when you want to do anything but just drive easy and will not get up to speed very quick. when you step in to it to pass, climb a hill or just to go faster it will fall on its face and lose speed and then pick back up very very slowy. The other day one of the techs had to prime it just to get it started back up. The codes we have found are as follows PO1093, PO404, PO101 is what I was told. One had something to do with the EGR. We cleared them and took it for a drive and the PO1093 came back very quickly and the others showed up soon thereafter. New fuel filters are one it and that didn't fix it. I even think that we had one dealer replaced the pick up tube and filter in the fuel tank. ( didn't know they had one in there?) We found one buliten about a pinched line come from or to the vac pump??? We have found that the Tech II shows that desired fuel pressure is higher than the fuel pressure readings we were getting from the engine and I know that theat could and is a very big problem to a diesel and I was wanting to know what should we do and if there was anything else to look at? :help2:

Thanks
Nathan and Kokosing Const. Co.

Injectors......?

Is that a big problem with LLYs I thought it was only the LB7s that had that problem?

The P1093 is a code that the LLY's usually throw when they are running a big program. I believe it is something to do with commanded rail pressure and actual? You aren't running a box of any kind on this truck are you?

The P1093 is a code that the LLY's usually throw when they are running a big program. I believe it is something to do with commanded rail pressure and actual? You aren't running a box of any kind on this truck are you?

no it shouldn't have a program on it. its a work truck and I doubt anyone would put one on it cause they tear the heck out of these trucks and it won't just do it under hard acceleration it does it all the time from my understanding and just clearing it and then starting it back up to back it out of the shop it'll reset it.

Take the techII and check FPRV. The valve maybe going bad in the seat area. If you can find the fittings check the vacuum on the low pressure side. There may still be a restriction from the tank to the low pressure gear pump.

I had a flexible fuel line from the frame to the engine starting to go bad. It was collapsing and blocking fuel flow.

If it will set the code that easy. Take an air hose and blow nozzle. Becareful not to over pressure the plastic tank. Use air pressure to help feed the engine. Let another person try and load the engine up and see if it makes a difference in the actual and demand pressures or with 1093 being set.

Just thinking, Ken.

I just returned from a long coast to coast trip with my 04 LLY 6.6 diesel 3500 crew pulling a cargo trailer loaded to the hilt with steal and cargo. The truck rang like a fine clock all the way out, however, upon returning home, I had my first real problem in almost 35,000 miles. While leaving the Yellowstone area the truck lost all power when I came to my first hill. I immediately pulled over and pumped the peddle several times and the engine responses. The engine light had come on when I lost power and stayed on. I called On-Star and had them run a diagnostic check on the engine and advised me that I had a, “fuel system failure” and that the closest Chevrolet dealership was some 75 miles away. I advised On-Star that I would try to make the trip to the dealership and had them call ahead.

We made the 75 mile trip to the very small dealership in northern Idaho and luckily most of the trip was down hill out of the mountains. Whenever I tried to apply any trottle over about 1800 rpm’s the engine would loose power and bog.

The problem………… a badly clogged fuel filter. I was amazed as I had just replaced the original filter at my local dealership some 4,000 miles earlier. The tech checked both my fuel in the tank and the fuel in my auxiliary tank (some105 gallons) and both were fine. I purchase bulk fuel when I find the price down on truck stops along the way and replenish my fuel from the auxiliary tank. The filter on the tank was also changed at the same time my engine fuel filter was and it checked out okay also. The filter was replaced with another GM filter and the truck never missed a beat the rest of the way home.

The technician thinks that something inside the GM filter failed and blocked the flow of fuel.

You may want to check the bleeder valve at the base of the filter and make sure the fuel flows right off. When mine was opened, nothing came out for several seconds until we tapped the side of the filter and then it started to flow.

Good luck.

Yeah we changed the fuel filter out for another brand (fleetgaurd) and it fixed the problem. Thanks for all the help.