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06-28-2021, 11:09 PM | #1 |
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Duramax towing “engine reduce power”
I was towing from Cincinnati to BG. When I hit the hills of Ky my
truck shut down with the reduce power limp mode. Had the truck towed home. I have replaced the fuel pressure Relief valve. Also installing a Air Dog fuel lift pump and replace the 6” Rubber fuel supply hose at the motor. Just trying to cover all the bases Has anyone else had this problem? Truck runs good with no problems without trailer . Thanks for any suggestions David |
06-29-2021, 12:00 AM | #2 |
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Re: Duramax towing “engine reduce power”
Does it give any DTC codes? Mine did it and I would get "low pan rail pressure". I tried everything, lift pump, relief valve. The only thing that fixed it was replacing the injectors. I know that's not what you wanted to hear but I fought it for awhile before replacing the injectors.
Dan
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Dan Foley SC 4698 |
06-29-2021, 02:33 PM | #3 |
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Re: Duramax towing “engine reduce power”
I think the code was PO 87. and a code for high intake
air temperature We was able to place a scanner on it while I was having trouble and all the injectors was balanced and appeared to be good. But I not a diesel mechanic . If problem happens again I was thinking injectors or cp3 pump. Both $$$ repair not knowing for sure which is bad. Thanks David |
06-29-2021, 02:59 PM | #4 |
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Re: Duramax towing “engine reduce power”
Which model Duramax? I have had that issue on LLY's and it is usually the relief valve. Replacing them seems to help for a short time. I have found shimming the original with a .040-.060 washer works well.
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06-29-2021, 07:24 PM | #5 |
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Re: Duramax towing “engine reduce power”
It is a 2008
I found a shop that changes the valve from a 2 stage Valve to a single stage. The 2 stage opens at a high pressure and stays open till The pressure drops below a low pressure setting The single stage opens and closes at same set point That my understanding of how the valves work.I could be mistaken on operation of the valves |
06-29-2021, 11:56 PM | #6 |
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Re: Duramax towing “engine reduce power”
On my LBZ 2007 Silverado was getting a low fuel pressure code. And would only happen when towing the trailer. Took it to a friend who has lots of experience with these engines and run a diesel repair shop. Replaced the injectors and problem cured. Not sure if this is the same issue you’re having but thought I’d share my experience.
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06-30-2021, 09:38 AM | #7 |
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Re: Duramax towing “engine reduce power”
Mine is also an LBZ. I bought a tuner that would check balance rates too. But it only checks them up to 1500 RPM. I also installed an AirDog system. The only thing that fixed it was replacing the injectors. I was told that it has to do with how much fuel was being returned .
Dan
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Dan Foley SC 4698 |
06-30-2021, 03:32 PM | #8 |
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Re: Duramax towing “engine reduce power”
Thanks, can the injectors be sent and tested or is it a waste
Of time and just replace the injectors? Looks like injectors are 350 to 450$ each for reman. |
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