I have an 85 M1009 with about 30K miles. I have owned it for about a year and have continually noticed that when under load and moving at about 45 mph I can put the pedal to the floor and not get much extra power and might even slow down a bit. But when I lift off and put the pedal at about 1/2 or slightly less, I get a better response from the engine and better acceleration.

What could be causing this? I have not done any mods to this engine.

Thanks

If its an automatic im 90% sure thats a transmission problem (probrably tv cable)

Is military all manual trans?

TH400, so then it might be a modulator issue?

ooohh i guess ill have to change my statement to IF its a 700r4

Not sure if a th400 would bog a motor like that. My 700 did that to me when the cable wasnt setup right, made my engine seem to miss.

The 400 has a vacuum modulator and not sure if that could cause similar problems but wouldnt hurt to check the line.

Is there black smoke when no more GO or loss of power?

How about insufficient fuel supply and/or pressure, a dirty air cleaner or a plugged up exhaust?

I think Lee is right.... check the lift pump.

Mine used to do exactly the same thing...but it has an sm465...no automatic. I turned up the fuel in the IP and the problem went away. Good luck

Sorry it took so long to get back.. I wasn't getting emails.

It is a th400
I just had the trans completely rebuilt... new seals/clutches/steel/etc...
I have a walbro pump 8-11psi
New air filter
Exhaust plugged up - possible.
Vacuum pump - The shop that rebuilt the tranny said there was no kick down becuase the detent is in the vacuum pump and it was wearing out. - I will replace it.
IP - I plan on turnig it up slightly.
Black smoke - No, none, ever!

Just out of curiousity, but how would you turn up the fuel in an 82 6.2? Is it an internal adjustment or external?

Sorry it took so long to get back.. I wasn't getting emails.

It is a th400
I just had the trans completely rebuilt... new seals/clutches/steel/etc...
I have a walbro pump 8-11psi
New air filter
Exhaust plugged up - possible.
Vacuum pump - The shop that rebuilt the tranny said there was no kick down becuase the detent is in the vacuum pump and it was wearing out. - I will replace it.
IP - I plan on turnig it up slightly.
Black smoke - No, none, ever!

There is no "detent" in the vauum pump, so I have no idea what your trans guys are trying to tell you - but they are telling you wrong. TH400 either has a vacuum modulator or a mechanical modulator. If your's uses vacuum then there is a variable vacuum valve mounted on your injection pump that tells your trans how firm to shift. not when to shift. There is also an electric kickdown shift mounted by your throttle linkage. That is NOT vacuum, it's electric. It is supposed to make it downshift when you stomp on the throttle, and it's hooked to a downshift solenoid in the transmission.

In regard to smoke -generally speaking, if you have it in high gear, throttle to the floor, and you hold the brakes on, you ought to see a little black smoke. If not, you're underfueled.

I doubt your exhaust is plugged. 6.2 does not take much air in, nor does it send much exhaust out and you've got dual exhaust, don't you? If anything, and if it was a C-code, I'd say check your heat-valve shutter in the driver's side exhaust manifold. But, you've got a J-code, correct?

Sounds to me you've got 3.08 axles and a TH400 not kicking down to 2nd when you want it too, that's all. Such high gearing does not give a great throttle response.

It is internal to the injection pump

Banks has instructions in their install manual

http://assets.bankspower.com/manuals/429/96291-v2-web.pdf

This might work to. I had to remove the Assets part of the address. http://bankspower.com/manuals/429/96291-v2-web.pdf

There is no "detent" in the vauum pump, so I have no idea what your trans guys are trying to tell you - but they are telling you wrong. TH400 either has a vacuum modulator or a mechanical modulator. If your's uses vacuum then there is a variable vacuum valve mounted on your injection pump that tells your trans how firm to shift. not when to shift. There is also an electric kickdown shift mounted by your throttle linkage. That is NOT vacuum, it's electric. It is supposed to make it downshift when you stomp on the throttle, and it's hooked to a downshift solenoid in the transmission.

He was prolly telling me that because he had never done a trans on a diesel. Mine is vacuum modulated.


In regard to smoke -generally speaking, if you have it in high gear, throttle to the floor, and you hold the brakes on, you ought to see a little black smoke. If not, you're underfueled.
Then I am under fueled. I had planned on turning up the fuel... I guess I will be doing it sooner.


I doubt your exhaust is plugged. 6.2 does not take much air in, nor does it send much exhaust out and you've got dual exhaust, don't you? If anything, and if it was a C-code, I'd say check your heat-valve shutter in the driver's side exhaust manifold. But, you've got a J-code, correct?

Sounds to me you've got 3.08 axles and a TH400 not kicking down to 2nd when you want it too, that's all. Such high gearing does not give a great throttle response.Yes, J-code and it was kicking down before the rebuild.

How do I adjust the down shift? Might it be in the TMs or can someone give me a link to a How-to?

Yes, J-code and it was kicking down before the rebuild.


There are different types of downshifts.

The kickdown that's supposed to happen when you stomp on the pedal in third is electric. There is an bracket holding an electric swithc by the injection pump. When you floor it the switch is turned on, and energizes a kickdown solenoid inside the transmission.

Other type of shifts are determined by the vacuum regulator on the injection pump and the modulator on the trans. Neither will work right unless the vacuum pump works.

how do I adjust each one?

how do I adjust each one?

No independent adjustment. Moving the switch effects all the internal contacts equally. There's nothing in there thats critical anyway. All for emissions except for the torque-converter clutch cut-out.