Help code 1093 06 Duramax Limp Mode

CorvetteMike · July 11, 2006

This truck is a head banger, I have an 06 2500HD Duramax 6.6 Allison 6sp. AT. The truck has 4" strait exhaust and an Airraid filter kit.

The problem is when you are in the throttle the truck throws a code for low fuel rail pressure. The truck as 24K on the clock and the dealer has changed the fuel filter several times, the injectors, the pump, the glow plugs and few other items but they do not know what the problem is yet. Any thoughts? Restriction in the line somewhere? Could I be making to much power for the stock fuel system? Maybe add a fuel pump and new pickup? The truck only does it when accelerating, passing or going up hill under throttle, any thoughts would be great and a fix deserves a prize.

GM-Tech · July 11, 2006

They need to look at the fuel pressure relief valve that's in the rear of the left fuel rail. Seen several of these. It'll dump fuel back through the return causing loss of pressure when under severe load or acceleration.

You can identify this by a u-shaped loop of hose at the rear of the fuel rail on the driver's side. Disconnect this hose and NO fuel should come out under any circumstances when it's running. If the relief valve is bad, ramping up the pressure will turn that line into a garden hose of diesel fuel.

The fuel rail has to be replaced to fix it.

CorvetteMike · July 11, 2006

This truck is a head banger, I have an 06 2500HD Duramax 6.6 Allison 6sp. AT. The truck has 4" strait exhaust and an Airraid filter kit.

The problem is when you are in the throttle the truck throws a code for low fuel rail pressure. The truck as 24K on the clock and the dealer has changed the fuel filter several times, the injectors, the pump, the glow plugs and few other items but they do not know what the problem is yet. Any thoughts? Restriction in the line somewhere? Could I be making to much power for the stock fuel system? Maybe add a fuel pump and new pickup? The truck only does it when accelerating, passing or going up hill under throttle, any thoughts would be great and a fix deserves a prize.

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GM TECH;

THANKS for your time as I know it is valuable. I will ask the dealer to make sure they check it and get it replaced. The fuel rail was replaced in April when the other items were done. I think that some of the dealers are lacking a good DMax tech or maybe just don't want to deal with it as the truck was bought in So. Fl. not here by my house.

I would like to ask if you think a lift pump by the tank would offer more supply and is worth the expense or does the stock system have the volume to keep 400 hp happy and would you know the pressure and volume a lift pump would need to suppy.

Thanks,

Mike

PS. I hope your health is better now. If you are ever in the Tampa area and need a day of fishing just let me know and we get the boat fueled up.

GM-Tech · July 11, 2006

Which fuel rail was replaced? And for what reason?

As for a lift pump... don't waste your money. Not only would it not help, it might actually be more of a problem in the form of a restriction. The "lift" or supply pump is part of the high press. pump, which is capable of some 28,000 psi. Working properly, it does the job quite well and needs no help from some add on pump.

CorvetteMike · July 23, 2006

They need to look at the fuel pressure relief valve that's in the rear of the left fuel rail. Seen several of these. It'll dump fuel back through the return causing loss of pressure when under severe load or acceleration.

You can identify this by a u-shaped loop of hose at the rear of the fuel rail on the driver's side. Disconnect this hose and NO fuel should come out under any circumstances when it's running. If the relief valve is bad, ramping up the pressure will turn that line into a garden hose of diesel fuel.

The fuel rail has to be replaced to fix it.

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Problem fixed today (so far) with a fuel pressure regulator. I hope it does keep it fixed. The new injection pump was still leaking down and after a few hints to the service guy that the regualtor may be bad they replaced it and presto it seems fixed. Wonder why they would not check it first but I guess they think always know more.

Thanks for your time and help