Water in fuel maybe, M988

[M988Tarvin]

I took out 10g of diesel. I didn't see any water in it. Hard to tell in a gas jug. I will drive it see if it helps. Ima order a filter and new glow plugs today. Get it all changed out. And go from there

 

[M988Tarvin]

Up date. Drove the m998 about 10 miles it's still doing the same loading up at idle. Runs fine on the rd

 

[ken]

A ten mile run probally used about a gallon. Do you have a laser thermometer? You can check each exhaust port to see if any of them are running cooler at idle. If so, you may have a dribbling injector. If it was full on sticking the engine would have a miss. As a last ditch before you pull any injectors run some Lucas injector cleaner through it. Double the dose on the bottle and burn a few gallons through it. Is there any pinging or knocking noise from the engine under a load?

 

[M988Tarvin]

I just got back from another 10 mile run.so 20 on it since the tank flush. And if u drive it normal, under 40 it will surge in power occasionally. And by the time u go to turn into a gas station and turn it off. it has already is loaded up to where o have to go to neutral and hold it at wot to clear it out before I kill it. Or else it's very hard to start back. I will do the temp gun tomorrow that's a great idea thanks!!

 

[Action]

Your signature line is blank. What drivetrain is in your HMMWV? I know the 4l80e uses a throttle position sensor at the injection pump. When that gets out of line or dirty, it can cause odd isuues.
I don't know if the N/A motors have that or not.

 

[M988Tarvin]

6.2l N/A 3 speed I think it's a turbo 400 trans

 

[doghead]

Did you power wash the engine as well?

 

[ken]

Yea I'm thinking at this point it's time to replace the injectors. Water in the fuel may have been the straw that broke the camel's back. After all, they are at least 20 years old. You really can't go by mileage with a Humvee. They may have spent a lot of time in the woods in low gear. Where it can burn a tank of fuel and only go 50 miles. There is no way to know how many hours are on the engine. It's possible the nozzle seats could have rust now and may not be sealing off when the needle reseats. This would let them dribble and fuel would puddle on top of the pistons. If this is happening, You might not want to drive it until you swap the injectors. Raw fuel will wash the oil off of the cylinder walls and accelerate piston ring wear. Check the oil, is it thin? Does it smell like Diesel at all? You might want to change it when you swap the injectors. Even if it was done recently.

 

[M988Tarvin]

It's done!! I drove it to my brothers house today and it loaded up and died in his drive way. It's on its way to the diesel shop for repairs. Will keep u updated.

 

[M988Tarvin]

It's getting fuel to filter, ij pump, and to #1 injector. I loosened the #1injector line and turned it over. I got fuel dribbling out of it.

 

[M988Tarvin]

UPDATE!!!!! sorry it's been so long but I got the humvee back today. Drove it about 80miles. the shop replaced the injection pump with a new built 6.5l pump from a Silverado 3500.the top over had to be reused. But it runs stronger than ever, it even rolls a little coal when u rlly get in it. But it's still slow lol. Thanks to everyone for the help btw bill for service was $1060 out the door.