Humvee Speed

[spyderx]

I recently received my first Humvee a 1986 998 with 6.5 GEP two door truck body. It's pretty clean. The main thing is it seems sluggish to get to get to speed. I understand it's a Humvee but my father has two Humvees a 1987 6.2 998 four door and a 1994 6.2 (Jasper Rebuild) 998A1 two door. His 998A1 gets to 60 in what feels like 10-15 seconds while mine takes closer 45 seconds if not 60 second.

Im not complaining, my father has had his first 998 for almost a year so I never expected it to be fast. Then his new 998A1 just takes off so quickly. Is it the 242 transfer case? Is the 3L80 on the A1 timed differently?

What do you think?

 

[jeffy777]

I recently received my first Humvee a 1986 998 with 6.5 GEP two door truck body. It's pretty clean. The main thing is it seems sluggish to get to get to speed. I understand it's a Humvee but my father has two Humvees a 1987 6.2 998 4 door and a 1994 6.2 (Jasper Rebuild) 998A1. His 998A1 gets to 60 in no time feels 10-15 seconds while mine takes closer 45 seconds if not 60 second.

Im not complaining, my father has had his first 998 for almost a year so I never expected it to be fast. Then his new 998A1 just takes off so quickly. Is it the 242 transfer case? Is the 3L80 on the A1 timed differently?

What at do you think?

First off your dad sounds cool! All the woman must want him. You probably can't keep a girlfriend with him around.

I have no clue why one is faster than the other. Maybe it is the good juju of your dad that makes it go so good.

 

[Bravojmc]

I recently received my first Humvee a 1986 998 with 6.5 GEP two door truck body. It's pretty clean. The main thing is it seems sluggish to get to get to speed. I understand it's a Humvee but my father has two Humvees a 1987 6.2 998 4 door and a 1994 6.2 (Jasper Rebuild) 998A1. His 998A1 gets to 60 in no time feels 10-15 seconds while mine takes closer 45 seconds if not 60 second.

Im not complaining, my father has had his first 998 for almost a year so I never expected it to be fast. Then his new 998A1 just takes off so quickly. Is it the 242 transfer case? Is the 3L80 on the A1 timed differently?

What at do you think?

Has he turned his pump up...?

 

[3jacks]

Is the 2 wire connector that goes from your time delay module and Cadillac valve unplugged? That keeps your fan clutch on all the time and it's a pretty decent loss of power.

 

[Bravojmc]

Is the 2 wire connector that goes from your time delay module and Cadillac valve unplugged? That keeps your fan clutch on all the time and it's a pretty decent loss of power.

Good call^

 

[nspctr1]

Can you provide a pic of said connector?

 

[3jacks]

Can you provide a pic of said connector?

driver's side, the two wire connector. Plug it in then unplug it. If your fan clutch isn't stuck you will see it move about 1/4".

 

[Action]

The fan will move front to rear and you should hear a noticeable difference when you unplug that connector. If you cant tell a difference one way or other, you will need to work on that system.

 

[infidel got me]

His foot is heavier than yours!!!! Turned up fuel, fuel filter, caliper hanging up, scared ?????

 

[frank8003]

If you want a truck for the highway then buy a highway truck.
Raptors are nice.
http://driving.ca/chevrolet/auto-news/entertainment/muscle-trucks-here-are-7-of-the-fastest-pickups-of-all-time
The truck you have is to help soldiers stay alive, eat, fight.
It is a tactical military vehicle.

 

[jeffy777]

Has he turned his pump up...?

What does that mean? I am actually the dad. The 998A1 is weirdly responsive. My 998 and his(my sons) 998 drive like school buses. They move well but the A1 takes off like a ordinary car. Good acceleration and moves to speed well.

 

[jeffy777]

Is the 2 wire connector that goes from your time delay module and Cadillac valve unplugged? That keeps your fan clutch on all the time and it's a pretty decent loss of power.

That may be it. I don't remember his getting up to temperature as we ran our test circuit and both of mine got up to temperature and I could hear the fan cycle. Though I do not know if that is it, his is a 6.5, and may not get up to temperature as fast. I told him that we have to go through cycles of maintenance and test after we do different things. Once we finish initial maintenance cycles I will test that. I think his runs well. He won the lottery getting a unit with new engine, new exhaust and new generator. It is ugly though. I will post pictures tomorrow.

 

[Bravojmc]

What does that mean? I am actually the dad. The 998A1 is weirdly responsive. My 998 and his(my sons) 998 drive like school buses. They move well but the A1 takes off like a ordinary car. Good acceleration and moves to speed well.

Here is a link http://www.flashoffroad.com/Diesel/injectionpump/mechanicalpump.htm

 

[3jacks]

If you want a truck for the highway then buy a highway truck.
Raptors are nice.
http://driving.ca/chevrolet/auto-news/entertainment/muscle-trucks-here-are-7-of-the-fastest-pickups-of-all-time
The truck you have is to help soldiers stay alive, eat, fight.
It is a tactical military vehicle.

i don't think the op was talking about highway speed. It was acceleration compared to other hmmwv's in their family. You are prob very family with the things that may affect acceleration in a hmmwv...why not help the guy out and give him some things to check or maybe teach him something about his new vehicle?

 

[jeffy777]

i don't think the op was talking about highway speed. It was acceleration compared to other hmmwv's in their family. You are prob very family with the things that may affect acceleration in a hmmwv...why not help the guy out and give him some things to check or maybe teach him something about his new vehicle?

That is true he was curious why the one comes up to speed so easy and the other two are more sluggish.

 

[Bravojmc]

i don't think the op was talking about highway speed. It was acceleration compared to other hmmwv's in their family. You are prob very family with the things that may affect acceleration in a hmmwv...why not help the guy out and give him some things to check or maybe teach him something about his new vehicle?

What he said.....^

 

[Action]

That may be it. I don't remember his getting up to temperature as we ran our test circuit and both of mine got up to temperature and I could hear the fan cycle. Though I do not know if that is it, his is a 6.5, and may not get up to temperature as fast. I told him that we have to go through cycles of maintenance and test after we do different things. Once we finish initial maintenance cycles I will test that. I think his runs well. He won the lottery getting a unit with new engine, new exhaust and new generator. It is ugly though. I will post pictures tomorrow.

After you finish initial maintenance cycles, you will test the fan????? It takes less than 5 seconds to unplug it....

Would the faster of the 3 happen to have a "P" on the trans shifter?

 

[jeffy777]

After you finish initial maintenance cycles, you will test the fan????? It takes less than 5 seconds to unplug it....

Would the faster of the 3 happen to have a "P" on the trans shifter?

No it does not have park it is not a 4L80 transmission.

Initially I do not care about any thing other than checking components, changing fluids, and lubricating everything that moves. I got two HMMWV's in one day. It was 100 degrees I got through two pages of my three page planned initial maintenance. During drive tests we checked the cooling and no HMMWV overheated. Operationally that is acceptable. It is a process. I do not think the 998 with the GEP 6.5 engine had the fan permanently engaged, at least it did not sound like it was. I know it only takes a few minutes to unplug and test. It was not an objective of mine to make it run a peak performance. My objective was to make sure it was it was safe and did not destroy itself because of use. I do not like to do but a few drive tests until I complete my inspection and maintenance routines.

I like to do an inspection and then a initial drive test to get a feel for areas that I may want to underline for greater inspection, maintenance or repair. The 998A1 took off effortlessly and really acted light and nimble (for a hmmwv). My son was wowed by it. Though it has issues as well. Through maintenance and testing we have things on the repair list so it is not all roses.

 

[tage]

Tacticool
Um like they said. It's a truck

 

[Bravojmc]

Tacticool 
Um like they said. It's a truck

That heat kickin up again down there...!?
Or is it that time again..? Lol