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I recently bought a 28ft rockwood 5th wheel 6700lbs so I had the sell my beloved tacoma. I figured a diesel would be perfect to tow the 5th wheel 3-8hr drives, after looking around a bit I found out my sisters husbands father would sell me his well maintained 2008 GMC 2500HD with 113k miles on it, he no longer needed it since he works in the city and only bought the truck to tow his 5th wheel which he no longer has. Hes been driving a civic for the last 2 years and the truck sat on the side yard only being started and driven to keep form getting stale. Before selling it to me he took it to the shop the guy recommended all fluid change plus fuel filter and housing. So I went to Reno from Redding to pick it up , drove it back from Reno, no issues. Once I got it home, I drove it back and forth from work for about a week. Even took the 4,000lbs boat to the lake over the weekend, no issues. Until I hooked the 5th wheel up, and tried going to the coast. As soon as I hit the mountains, boom! P0087! Limp mode on tight, steep, narrow and windy roads. Not fun. Did a little bit of research on the forum, went ahead and replaced the fuel filter (even though it was still new), will be adding the PPE fuel rail plug, and FASS lift pump. I've checked the lines and none seem to be pinched or soft. The previous owner has never had this issue and I believe him. I'm really thinking that it might of been something that they did at the shop when he took it in. Any help would be appreciated.

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Those lines just get soft over time; not much you can do about it. The lift pump and rail plug will help, but if you're going that far into it and plan on keeping the truck for a while I would do fuel lines as well; they're 12 years old at this point.

What were the driving conditions when you threw the code? You mentioned you were in the hills, but were you using the manual mode or did you just have it in Drive? With your LMM you should always have it in Tow/Haul when pulling ANYTHING (regardless of weight) and when pulling that camper it should be in Manual with 6th gear locked out (push the + button until 5 is displayed). On steep grades, I would say you might probably want to lock out 5th as well. Target RPM range is 1800 to 2200 cruising, but on grades you're going to be around 3000 rpm under a load. If the truck had to make a big downshift to get up a hill under a load, that would have exacerbated any deficiencies in your fuel delivery that wouldn't have been noticed running empty.

Welcome to the forum, and enjoy your new truck.
 

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With a 12 year old truck electrical, rubber hose and built up sludge or corrosion inside of lines are just something to be expected unfortunately. With new fluids things can break loose....... Good luck getting it sorted.
 

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Discussion Starter #5
I found the culprit. I Don't know how I missed it the first time but I rechecked all the lines and found a major pinch. Still gonna install the plug and lift pump.
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Those lines just get soft over time; not much you can do about it. The lift pump and rail plug will help, but if you're going that far into it and plan on keeping the truck for a while I would do fuel lines as well; they're 12 years old at this point.

What were the driving conditions when you threw the code? You mentioned you were in the hills, but were you using the manual mode or did you just have it in Drive? With your LMM you should always have it in Tow/Haul when pulling ANYTHING (regardless of weight) and when pulling that camper it should be in Manual with 6th gear locked out (push the + button until 5 is displayed). On steep grades, I would say you might probably want to lock out 5th as well. Target RPM range is 1800 to 2200 cruising, but on grades you're going to be around 3000 rpm under a load. If the truck had to make a big downshift to get up a hill under a load, that would have exacerbated any deficiencies in your fuel delivery that wouldn't have been noticed running empty.

Welcome to the forum, and enjoy your new truck.
I Just had it in drive with tow on. But ill be sure and kick it down to manual next go.
 

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I Just had it in drive with tow on. But ill be sure and kick it down to manual next go.
Your truck loves 2000 rpm when pulling. It just feels more alive. Your transmission will also love it because it won't have to work as hard, either. You'll notice transmission temps are lower when you're pulling with RPM in the 2000 range than if you let the truck bring itself down to 1600 or so.
 

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I don't know if you have fixed this or not but here is a description how:


Since you are doing them you should at least do the one you found, plus the one on the drivers side just inside the frame. Another one that can cause the same issue and is often overlooked is the one at the top of the fuel tank running to the Quick Connect fitting.

One tip, the TSB describes cutting two slots in the swagged fittings to get them off. I found if you simply cut one slot, put the tip of a large screwdriver in the slot and twist the driver with a wrench it will spread the fitting and it will fall apart without the necessity to cut the second slot.
 

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Discussion Starter #9
I don't know if you have fixed this or not but here is a description how:


Since you are doing them you should at least do the one you found, plus the one on the drivers side just inside the frame. Another one that can cause the same issue and is often overlooked is the one at the top of the fuel tank running to the Quick Connect fitting.

One tip, the TSB describes cutting two slots in the swagged fittings to get them off. I found if you simply cut one slot, put the tip of a large screwdriver in the slot and twist the driver with a wrench it will spread the fitting and it will fall apart without the necessity to cut the second slot.
I have not done anything yet, I'm still waiting on the lift pump and a dremel I ordered (don't wanna go in with my grinder). I'm hopping I can get at least 6 inches off the hose that comes with the lift pump kit. I checked the rest of the fuel lines really good and all seem to be ok plus going from vacuum to 8psi I don't think it will pinch again. Thanks for the advice I'll give the one cut a go.
 

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I found the culprit. I Don't know how I missed it the first time but I rechecked all the lines and found a major pinch. Still gonna install the plug and lift pump.
View attachment 1078199
If you're careful, and maybe a little lucky, placing a high quality, wide hose clamp around that hose just enough to make it round again can be the fix instead of replacing the hose itself. Worth trying for the $2 it would cost for the hose clamp. Mine has been on for about 8 or 9 years now and seems to work just fine.
 

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I have not done anything yet, I'm still waiting on the lift pump and a dremel I ordered (don't wanna go in with my grinder). I'm hopping I can get at least 6 inches off the hose that comes with the lift pump kit. I checked the rest of the fuel lines really good and all seem to be ok plus going from vacuum to 8psi I don't think it will pinch again. Thanks for the advice I'll give the one cut a go.
Vacuum to 8 psi? I’m confused. Can you explain that more?
 

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Vacuum to 8 psi? I’m confused. Can you explain that more?
He's referring to going from pull to push in the fuel lines. Instead of pump pulling fuel from the tank, lift pump will add positive pressure in the lines.
 

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Discussion Starter #13
Everything came in today so tomorrow I'm gonna replace that line and install the LP and plug. I do have a question for you guys, from what I hear is if the LP dies or something happens with it you are shit out of luck and the truck will not run. What are your guys thoughts on running some T's and valves setting up some sort of by-pass as a back up?
 

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Welcome to the DF! Many people have done the bypass setup with no problems and I personally prefer a valve setup on my lift pump. Don’t know what lift pump you have but my air dog setup is a flow through design and have ran the 01 with the lift pump not running for 500 miles with no problem.
 
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Welcome to the DF! Many people have done the bypass setup with no problems and I personally prefer a valve setup on my lift pump. Don’t know what lift pump you have but my air dog setup is a flow through design and have ran the 01 with the lift pump not running for 500 miles with no problem.
I thought I had read the Air Dog had a flow through design, but didn't want to give incorrect info.
 

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I would not worry about the reliability of the lift pump. I use this pump Airtex External Electric Fuel Pumps E8153 and it has been rock solid reliable. Original installed -7/2010. Just to make sure I don't get caught somewhere that I can't get a replacement, I just keep another one under the back seat.
 

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So I put the LP in plug and fix that pice of hose so I thought, took it for a test drive everything seemed fine till this morning when I started her up and she was pouring fuel. I think I might have cut to deep getting that crimp off so now I’m gonna try and stretch the hose over the crimp see how that goes

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I do not believe you are going to be able to stretch that hose over the crimp ring.

You might try cutting off the crimp ring and slipping the hose on the line past where you created the leak. Use two worm gear camps about 1/2" apart to secure it to the line.
 
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