Power issue. Any help would be appreciated.

[996owner2021]

So I'm brand new to this hmmwv world and recently bought my first one back in October. Its been an expensive education to say the least... replaced alot of key parts and still can't figure out the power issue going up hills.
I've looked at pump, and when I first got it it was caked in just utter gunk. After cleaning and driving, I wouldn't call it a drip leak but something is getting through.
I recently noticed the last Two Injectors on alternator side are dribbling either oil or diesel or both. Very very small . Tried to look at injectors but getting the right socket is a pita. I know it's needs to be thin walled now.

Called every in town and of course no one will work on it. It's titled as 88 but has a gm 6.2 stamp 1990 with a date of service of 09 94. So I'm not sure what the heck went on there but that's a moot point for now.

Any help with the power issue would be greatly appreciated.

 

[Action]

I had a similar issue with slowing down on hills, especially with less than 1/2 tank. The IP will strain to keep it running, if the lift pump dies. My lift pump was leaking around the seam and the diaphragm had failed. I also found debris in the one-way valve on fuel filter inlet.

 

[996owner2021]

I had a similar issue with slowing down on hills, especially with less than 1/2 tank. The IP will strain to keep it running, if the lift pump dies. My lift pump was leaking around the seam and the diaphragm had failed. I also found debris in the one-way valve on fuel filter inlet.

Thank you. I did also notice that the goofball I bought this from never replaced the Injector fastener bolts on said injectors where leaking is occurring. Any idea where to find those?

 

[TOBASH]

You could have several problems.

You could have a bad lifter pump. You could have a dirty sock inside of the fuel cell. You could have a fuel cell vent that is clogged. You could have an injection pump that is not clocked properly and not providing enough fuel. You could have bad injectors.

 

[996owner2021]

You could have several problems.

You could have a bad lifter pump. You could have a dirty sock inside of the fuel cell. You could have a fuel cell vent that is clogged. You could have an injection pump that is not clocked properly and not providing enough fuel. You could have bad injectors.

Thank you. When it does go uphill. It gets really loud and rpms scream, black smoke dumps out as well. So it not getting burned correctly. Leaning towards the injector side of things as well as pump.

 

[TOBASH]

If the RPM scream, perhaps this is a torque converter or transmission clutch issue.

If the tranny is working properly, why would the RPM scream unless the tranny is downshifting too much or the clutches are worn?

 

[996owner2021]

If the RPM scream, perhaps this is a torque converter or transmission clutch issue.

If the tranny is working properly, why would the RPM scream unless the tranny is downshifting too much or the clutches are worn?

That could be it. I did notice when playing with hl/h/n/l in neutral with truck on that there was a grind. I read other forums from truck drivers with 6.2s and they say there is a trick to increase rpms and shift just as they fall....idk, any thoughts?

 

[Barrman]

Black smoke means too much fuel. Or, not enough air. How is your air filter?

Snap-On makes a special injector socket for the 6.2/6.5. A 32 mm open end will work sometimes.

The injector lines seal to the injectors or the injection pump with a very fine tolerance fit. A single spec of dirt will cause a dribble. Don’t just tighten the fitting as the ends could crack. Take it apart, clean and try again. Sometimes several cycles of trying are needed.

If the line is leaking, fuel will pool inside the injector line nut. If the return line is leaking you will get a drip with a dry injector line fitting.

Fellow forum member Gimpyrobb lives there in your town. He has 6.2 and 6.5 experience. Maybe send him a PM to see if he could consult.

Finally, I have to ask. Have you ever driven a 6.2 powered anything before? Without a turbo they don’t really like hills. I tells passengers to never even think the word, much less say it while we are driving. It might scare the engine and we could loose 5 mph on a flat stretch.

 

[TOBASH]

First of all, NEVER shift the transfer case with the engine on. Secondly, keep the thing in H, NOT HL.. Thirdly, if you put it in L, you will over-rev the engine. L is only for rock climbing/sand/low speed situations.

Also, the prior poster immediately above me (Barrman) is correct. You have a LOW horsepower non-turbo unit with a 3 speed tranny that will NEVER do over 45 MPH without screaming, and will never do over 50 MPH for over 2 minutes without damaging the engine (unless you're JuanPrado).

 

[Action]

Shut the engine iff when you shift the transfer case.

 

[996owner2021]

Black smoke means too much fuel. Or, not enough air. How is your air filter?

Snap-On makes a special injector socket for the 6.2/6.5. A 32 mm open end will work sometimes.

The injector lines seal to the injectors or the injection pump with a very fine tolerance fit. A single spec of dirt will cause a dribble. Don’t just tighten the fitting as the ends could crack. Take it apart, clean and try again. Sometimes several cycles of trying are needed.

If the line is leaking, fuel will pool inside the injector line nut. If the return line is leaking you will get a drip with a dry injector line fitting.

Fellow forum member Gimpyrobb lives there in your town. He has 6.2 and 6.5 experience. Maybe send him a PM to see if he could consult.

Finally, I have to ask. Have you ever driven a 6.2 powered anything before? Without a turbo they don’t really like hills. I tells passengers to never even think the word, much less say it while we are driving. It might scare the engine and we could loose 5 mph on a flat stretch.

Never had a diesel in my life!! Lol. Got in a really bad car accident on Easter, hit from behind and made sure I got rid of the 2 doors for what I thought would be biggest and baddest thing on the road. It's Definately a fun toy and I take great pride in working on it and bringing it back to good operational status but I gotta be honest, everyday I think I'm in over my head. I've gone through 6 batteries, 2 alternators 2 regulators, finally in green on voltage. replaced PC gearbox, differential seals, air filer, crack lines that I could, replaced tires, rhino lined everything, changed oil atleast 4 times along with what seems a weekly flush because the coolant keeps turning a brownish , and sometimes the hose on top of radiator into block seems like it doesn't have anything in it but when I turn heater on it starts to build pressure. I took it to one mechanic on beechmont, and within first 5 minutes I'm getting quoted a 4 to 5k job as he wanted to reseal the gaskets and whatever else which I think is extreme. If there are local guys, I would like to connect.

 

[996owner2021]

Noted about transfer case. Once I heard sound , I didn't force it. I shut it off and it went through the modes just fine without sound.

 

[Action]

Sometimes it’s not a joke when we call it a
High
Maintenance
Money
Wasting
Vehicle

the upper radiator hose tightens when the thermostat opens.
The coolant can be darkening from rust.
rhino lining everything probably caused most of your issues!
If it occasionally sound like a plane trying to take off and losing power, that is normal. It is your fan coming on.

 

[996owner2021]

Sometimes it’s not a joke when we call it a
High
Maintenance
Money
Wasting
Vehicle

the upper radiator hose tightens when the thermostat opens.
The coolant can be darkening from rust.
rhino lining everything probably caused most of your issues!
If it occasionally sound like a plane trying to take off and losing power, that is normal. It is your fan coming on.

When I say rhino line, more specifically hurculiner roll on, exterior only. What issues will that cause on a aluminum body?

 

[996owner2021]

Oil pressure sits at 40 when running, temp sits at 180 to just under 200 idling. I've heard fan kick on a few times when I run it around. Seems to get close to 230 and then back down to 190ish

 

[Action]

When I say rhino line, more specifically hurculiner roll on, exterior only. What issues will that cause on a aluminum body?

It was a joke cuz i cant stand bedliner on vehicles. Nothing personal.

 

[996owner2021]

It was a joke cuz i cant stand bedliner on vehicles. Nothing personal.

Haha. I gotcha. It's all personal preference at end of day and I go back and forth whether it was worth it.

 

[Mogman]

I am with Action, I have never seen bed liner applied to a vehicle more than a few years old that did not look like hell, I would not touch one with a 10 foot pole.
It appears the main reason for doing this is they do not want to do proper prep work before paint and somehow expect the bed liner will magically stick anyway, now had someone done this with regular paint the troubles that would show up later can be rectified, not so with bed liner.
Sorry to dump on you but had you asked before doing this I am sure you would have received a ton of advice against it.
Now if you plan on trashing it totally out in the next few years that would be OK but long term you have devalued the vehicle immensely

 

[996owner2021]

I am with Action, I have never seen bed liner applied to a vehicle more than a few years old that did not look like hell, I would not touch one with a 10 foot pole.
It appears the main reason for doing this is they do not want to do proper prep work before paint and somehow expect the bed liner will magically stick anyway, now had someone done this with regular paint the troubles that would show up later can be rectified, not so with bed liner.
Sorry to dump on you but had you asked before doing this I am sure you would have received a ton of advice against it.
Now if you plan on trashing it totally out in the next few years that would be OK but long term you have devalued the vehicle immensely

I am with Action, I have never seen bed liner applied to a vehicle more than a few years old that did not look like hell, I would not touch one with a 10 foot pole.
It appears the main reason for doing this is they do not want to do proper prep work before paint and somehow expect the bed liner will magically stick anyway, now had someone done this with regular paint the troubles that would show up later can be rectified, not so with bed liner.
Sorry to dump on you but had you asked before doing this I am sure you would have received a ton of advice against it.
Now if you plan on trashing it totally out in the next few years that would be OK but long term you have devalued the vehicle immensely

Here's how it turned out. I mean I was just looking for something to hide the job from previous owner

 

[996owner2021]

Here's how it turned out. I mean I was just looking for something to hide the job from previous owner
View attachment 854330

Additionally as I assume someone will mention the red spot on board underneath, it was a bad gearbox, which has been replaced. Install was about 3 hrs and alil tricky, but got it done %)