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2006 LLZ
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Discussion Starter · #1 ·
2006 2500 towing 5500 lbs through North Carolina mountains let me move 750 miles before getting off the interstate to what seems to have gone into limp mode. Multiple random codes when scanned at advanced auto. P0087 code confirmed from a different scanner and no other codes except my glow plug 5 circuit (known). Cleared code(s), offloaded trailer and the truck is functioning just fine without weight behind. Fuel lines under the hood look good, no kinks no long time wear n tear. Will check fuel pressure valve. Any other thoughts? I rarely haul so… quite confused.
 

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2010 crew cab dually
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228 Posts
My 2010 did the same thing I believe it's attributed to our aging fuel systems

Even if the soft lines look normal they have 15+ yrs of diesel soaked into them and aren't as rigid as they used to be under high demand the cp3 is vacuuming them closed

Replace all flexible lines after that is eliminated if problem persists shim fuel pressure relief valve
 

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7,489 Posts
Tons of posts about P0087 and possible solutions, fuel filter head, fuel lines, injectors, fuel pump, lift pump, and many, many more. The question is what is not working correctly with YOUR truck?
 
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This happened to me with my 2007 LBZ on a 105º day while towing our 10k# TT. My fix was to shim the FPRV and I installed an AirDog II 165gph and the problem hasn't returned. I like shimming the FPRV over using a "race plug" since all the shims do is raise the spring rate of the FPRV so it'll still functions in case the CP3 over-pressurizes the fuel rail instead of pushing the over-pressure fuel through the injectors. My thinking is it's easier/cheaper to reset a P0087 code with my Edge Insight CTS2 monitor than it is replacing 8 injectors.
 

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As stated above it could be a lot of things that give the code. I’m willing to bet it’s the lines integrity that most likely showed when temps got increased around them causing them to soften up.

especially if it only did it the one time and you haven’t noticed anything else. A lot of people go straight to lift pump and FPRV but 80 percent of the time it’s another issue that is just band aided by them.
 

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2006 LBZ, 2009 LML, 2022 L5P. 1993 6.5 parked in the shed.
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Even a simple lift pump (like a Kennedy) is usually a cheaper fix than just about anything else and has some benefits too.

My LBZ started to loose prime on very hot days, after pricing out all the parts that might have been the issue I installed the pump. Problems went away and I get the plusses of having a pump.
 

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2006 LLZ
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Discussion Starter · #8 ·
Thanks for the input. A diesel mechanic took a look at the truck today and determined there was air in the fuel lines apparently from improper fuel filter installation. They concluded that should address P0087 without running in-depth diagnostics. Check engine has not popped back on yet. They insisted that I need to have the flex plate/torque converter investigated before getting back on the road home. I’ve had the truck in the shop before and have never had that recommended. He was referring to a kind-of ticking noise during idle but it’s not that noticeable. To me at least. Not sure how I feel about all that.
 
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