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Hmmwv Fuel Issue after IP replacement

RayGunSlayer

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Hey guys I need some help. So just recently started changing stuff on my hmmwv that needed to be fixed. One of these was the injection pump. It was leaking pretty bad when the vehicle was shut off so I figured since I have it down to get the transmission rebuilt, why not go ahead and change that. Well now it’s not running right at all. So mine was the 5149 version of the injection pump. Ordered a reman unit from melton because I really couldn’t find any at the time of looking. So theres two problems, the truck runs very rough and also it loses its prime after only about twenty minutes. I have no fuel leaks at all. Both ends of the hardline from the fuel pump to filter and the filter to the injection pump are tephlon taped and tephlon sealed with sealant. So no leaks, all hose clamps, injectors, injector lines are tightened down fully. Oh I also replaced the fuel pump as well since I did the injection pump. I have cranked until all cylinders were spraying fuel. Also I put a clear fuel line on the return side of the injection pump and I can’t see any air bubbles at all. The only thing I did different was I turned up the pump maybe 1/6th of a turn. It spits smoke out but it’s more of a blueish smoke and not black. It runs like not all cylinders are running and some times it will randomly smooth out for maybe 5 seconds then go back to choppy. The glow plugs all have been checked and work perfectly so it’s not those. I feel like maybe there is air still in the injection pump but it’s ran for about 15 minutes at idle and hasn’t made a change at all. Could turning the fuel up have thrown too much fuel into the combustion chamber to the point where it won’t fully explode? Like at this point I guess I’m just speculating because I have no idea what it could be. Thanks guys
 

Mullaney

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Hey guys I need some help. So just recently started changing stuff on my hmmwv that needed to be fixed. One of these was the injection pump. It was leaking pretty bad when the vehicle was shut off so I figured since I have it down to get the transmission rebuilt, why not go ahead and change that. Well now it’s not running right at all. So mine was the 5149 version of the injection pump. Ordered a reman unit from melton because I really couldn’t find any at the time of looking. So theres two problems, the truck runs very rough and also it loses its prime after only about twenty minutes. I have no fuel leaks at all. Both ends of the hardline from the fuel pump to filter and the filter to the injection pump are tephlon taped and tephlon sealed with sealant. So no leaks, all hose clamps, injectors, injector lines are tightened down fully. Oh I also replaced the fuel pump as well since I did the injection pump. I have cranked until all cylinders were spraying fuel. Also I put a clear fuel line on the return side of the injection pump and I can’t see any air bubbles at all. The only thing I did different was I turned up the pump maybe 1/6th of a turn. It spits smoke out but it’s more of a blueish smoke and not black. It runs like not all cylinders are running and some times it will randomly smooth out for maybe 5 seconds then go back to choppy. The glow plugs all have been checked and work perfectly so it’s not those. I feel like maybe there is air still in the injection pump but it’s ran for about 15 minutes at idle and hasn’t made a change at all. Could turning the fuel up have thrown too much fuel into the combustion chamber to the point where it won’t fully explode? Like at this point I guess I’m just speculating because I have no idea what it could be. Thanks guys
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Okay. Here is the grumpy old bubble buster guy who is going to rain on my parade... What IF you go back to where you were and then step by step let's figure this out. The way I read your post I see two things.

#1 - I (you) turned up the pump maybe a 1/6th of a turn. One Sixth of a turn is a LOT of turning on your injection pump. Can you put it back to zero and see what happens?

#2 - You ordered a reman IP. Do you still have that? Can the OLD one be put back so the truck will run?

As I was reading your post, I read two entirely different things. One is the new pump. Two was advancing the New or Reman 60 degrees. Before either of those were done your truck would crank. - Yes?
 

RayGunSlayer

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Location
Fort Oglethorpe, Georgia
.
Okay. Here is the grumpy old bubble buster guy who is going to rain on my parade... What IF you go back to where you were and then step by step let's figure this out. The way I read your post I see two things.

#1 - I (you) turned up the pump maybe a 1/6th of a turn. One Sixth of a turn is a LOT of turning on your injection pump. Can you put it back to zero and see what happens?

#2 - You ordered a reman IP. Do you still have that? Can the OLD one be put back so the truck will run?

As I was reading your post, I read two entirely different things. One is the new pump. Two was advancing the New or Reman 60 degrees. Before either of those were done your truck would crank. - Yes?
Lol I can only go back so much sadly. I do not have the old IP. I sent it in for a core refund, which now I’m wishing I didn’t since my old one ran better. I can definitely put the pump back to zero and I was honestly planning on it. The only reason I turned it up that much was because I read the entire article on Flash Off-road about turning up your pump. I did not try the truck while the pump was at zero since it’s harder to get to with it installed on the truck.
 

Mullaney

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Lol I can only go back so much sadly. I do not have the old IP. I sent it in for a core refund, which now I’m wishing I didn’t since my old one ran better. I can definitely put the pump back to zero and I was honestly planning on it. The only reason I turned it up that much was because I read the entire article on Flash Off-road about turning up your pump. I did not try the truck while the pump was at zero since it’s harder to get to with it installed on the truck.
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Good deal!! Sad that the old IP has gone back, but at least you could go back to zero on the new one. Then see where you are. Once you have it running more smoothly -- You could try a tiny motion away from zero. Lock it down and go driving. And just repeat those steps until it gets much better or a whole lot worse.
 

RayGunSlayer

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Location
Fort Oglethorpe, Georgia
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Good deal!! Sad that the old IP has gone back, but at least you could go back to zero on the new one. Then see where you are. Once you have it running more smoothly -- You could try a tiny motion away from zero. Lock it down and go driving. And just repeat those steps until it gets much better or a whole lot worse.
Thank you I appreciate the help. I’ll update you guys hopefully tomorrow if I am able to do it tomorrow
 

Milcommoguy

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Probably shouldn't have mess with it till one know what you got. It's not that hard to adjust in truck. What engine / set-up do you have. (note 5149 is 6.5 NA) Wonder if it was set-up correctly at Melon ?

What is and where did you smear this "tephlon" sealant?

If only a 1/16 turn... I would guess it would be difficult to see any difference till put under a heavy load... going for more power? then maybe a little more black smoke.

Holly smokes on that Melon, CAMO

 
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Maxjeep1

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Probably shouldn't have mess with it till one know what they got. It's not that hard to adjust in truck. What engine / set-up do you have. (note 5149 is 6.5 NA) Wonder if it was set-up correctly at Melon ?

What is and where did you smear this "tephlon" sealant?

If only a 1/16 turn... I would guess it would be difficult to see any difference till put under a heavy load... going for more power? then maybe a little more black smoke.

Holly smokes on that Melon, CAMO

Bloody hell. 1,800 is the cheapest/best option for a replacement? I hope my stuff lasts awhile. Really an unusual vehicle to have the opportunity to experience. Worth every penny if you still have pennies left.
 

Bulldogger

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You didn't mention that you bled the injectors. This is always a good idea after making changes to the fuel system. They can trap air and cause symptoms such as you describe.
BDGR
 

RayGunSlayer

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14
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Location
Fort Oglethorpe, Georgia
Probably shouldn't have mess with it till one know what they got. It's not that hard to adjust in truck. What engine / set-up do you have. (note 5149 is 6.5 NA) Wonder if it was set-up correctly at Melon ?

What is and where did you smear this "tephlon" sealant?

If only a 1/16 turn... I would guess it would be difficult to see any difference till put under a heavy load... going for more power? then maybe a little more black smoke.

Holly smokes on that Melon, CAMO

So yes my engine is the 6.5na. When I turn the fuel back down on it my next step after that is to re-bleed the entire system to see if it runs better. The tephlon tape and sealant was used on the fuel hardline where it connects to the mechanical fuel pump and the supply side of the IP. Yeah it was definitely expensive for a fully reman one but with the core refund it was 1,300 instead of 1,800
 

Milcommoguy

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Hey guys I need some help. So just recently started changing stuff on my hmmwv that needed to be fixed. One of these was the injection pump. It was leaking pretty bad when the vehicle was shut off so I figured since I have it down to get the transmission rebuilt, why not go ahead and change that. Well now it’s not running right at all. So mine was the 5149 version of the injection pump. Ordered a reman unit from melton because I really couldn’t find any at the time of looking. So theres two problems, the truck runs very rough and also it loses its prime after only about twenty minutes. I have no fuel leaks at all. Both ends of the hardline from the fuel pump to filter and the filter to the injection pump are tephlon taped and tephlon sealed with sealant. So no leaks, all hose clamps, injectors, injector lines are tightened down fully. Oh I also replaced the fuel pump as well since I did the injection pump. I have cranked until all cylinders were spraying fuel. Also I put a clear fuel line on the return side of the injection pump and I can’t see any air bubbles at all. The only thing I did different was I turned up the pump maybe 1/6th of a turn. It spits smoke out but it’s more of a blueish smoke and not black. It runs like not all cylinders are running and some times it will randomly smooth out for maybe 5 seconds then go back to choppy. The glow plugs all have been checked and work perfectly so it’s not those. I feel like maybe there is air still in the injection pump but it’s ran for about 15 minutes at idle and hasn’t made a change at all. Could turning the fuel up have thrown too much fuel into the combustion chamber to the point where it won’t fully explode? Like at this point I guess I’m just speculating because I have no idea what it could be. Thanks guys

Worry Wart here... I am a little concerned about the use of this "Tephion" or is it Teflon as it is not recommended on flare fittings. While one might think 'hell, can't be that thick" the seal is made at the flare and is a dry, clean, no nicks, burrs, or buggers and flare to flare square fit up IMO.

See >

Might break all the injector input feeds and crank engine over a few time to get fuel out to the injectors again. I think you said that ???

The picture of the Melon didn't look right to me. I didn't see the power advance lever ??? Passenger side. Might be a stock photo, might be losing my mind? (can't find it now 404 error)

To late now BUT old trucks sitting and IP's leaks go hand and hand. Cheap seal kit may have saved the day.

Any chance you sealed the injectors?

Between the lines, CAMO
 

RayGunSlayer

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Location
Fort Oglethorpe, Georgia
Worry Wart here... I am a little concerned about the use of this "Tephion" or is it Teflon as it is not recommended on flare fittings. While one might think 'hell, can't be that thick" the seal is made at the flare and is a dry, clean, no nicks, burrs, or buggers and flare to flare square fit up IMO.

See >

Might break all the injector input feeds and crank engine over a few time to get fuel out to the injectors again. I think you said that ???

The picture of the Melon didn't look right to me. I didn't see the power advance lever ??? Passenger side. Might be a stock photo, might be losing my mind? (can't find it now 404 error)

To late now BUT old trucks sitting and IP's leaks go hand and hand. Cheap seal kit may have saved the day.

Any chance you sealed the injectors?

Between the lines, CAMO
The reason I used the Teflon tape and sealant on those flared fittings is on both the injection pump inlet and on the fuel pump outlet I’ve had leaks happen even when tightening down the fitting all the way. I can very easily take it back off but that was the main reason that I did that. And also, my oil cooler lines for the engine oil is leaking at those fittings as well so I had originally planned on putting some on those as well. Those lines are brand new
 
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Milcommoguy

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The mechanical threads of the flare type coupling will not benefit from the use of tapes or sealants. The compression of the mating surfaces is the seal. Like I said ... Jacked up, dinged, busted, scratched flares under pressure can leak with the most minuet microscopic flaw. A proper fit-up can hold 1000's of PSI.

If for some reason one got a glob of the stuff going into the pump... there is a very fine input filter on the input line. See the DB pump exploded views on-line.

Careful on the tightening thing. Use two wrenches or good chance of twisting pump housing or crushing / tweek tubing.

This is going to be a good one. Good Luck........

No return, No re-fun, CAMO
 

RayGunSlayer

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Location
Fort Oglethorpe, Georgia
Okay everyone I think I may have found part of what my problem was. The first picture is where the IP was lined up before the new one was installed and the second one is where it’s installed now. On the first one you can’t see the line but it was perfectly lined up before. Now on this new pump I lined up the lines but if you look just to the right to where the line is at on the pump, the point where it starts to slope down to the drivers side bolt begins. Compare the location of the start of that slope on the IP before and after where it lines up at the block little triangle point. Timing definitely is off from what it looks. I believe that when rebuilding the old pump that Melton got, the line on the IP for timing was either worn off or they did it while rebuilding and so they cut a new line in the IP. They definitely don’t look the same to me but after all this work my brain could be playing tricks on me.
 

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Mullaney

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Okay everyone I think I may have found part of what my problem was. The first picture is where the IP was lined up before the new one was installed and the second one is where it’s installed now. On the first one you can’t see the line but it was perfectly lined up before. Now on this new pump I lined up the lines but if you look just to the right to where the line is at on the pump, the point where it starts to slope down to the drivers side bolt begins. Compare the location of the start of that slope on the IP before and after where it lines up at the block little triangle point. Timing definitely is off from what it looks. I believe that when rebuilding the old pump that Melton got, the line on the IP for timing was either worn off or they did it while rebuilding and so they cut a new line in the IP. They definitely don’t look the same to me but after all this work my brain could be playing tricks on me.
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It would be pretty amazing if that solves your problem! That is part of the wonder of working on your own vehicle. It is a 50/50 proposition. It will improve your situation or make it worse. Right?
 

Milcommoguy

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I' am not sure what I am seeing. I see a timing mark on cover just under return line, and no line on the pump of the left photo. Then a dirty line to the right on cover aligned to the pump right photo. This is a mess. Lines should be clear and pump centered more or less. The second picture looks to be more correct IMO, If Melon did their home work ???

This is not like a gas engine distributor where one can spin it all around. Not a lot of wiggle room to set timing. Timing usually is in line to line for a ball park starting point. Any adjustment may result in just a little off line up to 1/8 inch +/-. Many variables enter into getting it right, temperature, altitude, air flow, quality of fuel, injectors, etc. Trying to rotate pump in it's self is a challenge with 8 steel lines going in all direction even though the movement is in fractions. I have a custom rotating tool and then go back and release any pre-loaded lines. PITA but one doesn't need a cracked line.

Electronic timing system get close results or my preferred way is to dial it in with meter and see how it runs. Then real world load, live, hard WOT on a dyno or a couple of performance road test. Very slight movements for complete burn efficiency. Messing with fuel delivery when properly set up...just make more coal.

Seeing double, CAMO
 

Action

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Are the alignment marks all in the exact same position? I have always thought when the engine is built the first tine, someone makes the mark. Meaning if the pumps are swapped between 2 engines and timed correctly, the lines might not line up.
 

Mullaney

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Are the alignment marks all in the exact same position? I have always thought when the engine is built the first tine, someone makes the mark. Meaning if the pumps are swapped between 2 engines and timed correctly, the lines might not line up.
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I guess that could be possible - but that mode of creating the mark would suck in a big way.
Would almost be like creating the timing mark on the harmonic balancer after it is on the truck.
 
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