M936 no power

[Deuce007]

Hey guys,
We just bought a 1984 M936 with the cummins NHC250 motor and on the drive home it seemed like it didn't have much of any power. Now I know that it is a non-turbocharger engine but on a few hills the speed would drop off to 10 mph. During the climb, it didn't produce any black smoke whatsoever so I assume that it is a fuel shortage. Then the next day I drove it a half mile on flat ground and realized I was pedal to the floor and only going about 25 mph. Do you think it could be bad a bad fuel filter? If so, where is the fuel filter located?

 

[Castle Bravo]

While checking the fuel filter is a good idea, keep in mind that the power to weight on a 936 is like 150 lbs/hp.

Here is a video I took of driving a M936 up a hill.

http://www.youtube.com/watch?v=aAso5kTlgGQ

 

[Old Lincoln County Iron]

That M936 looks very familiar! On flat ground I was running 62-63 according to the Speedo. Did not have a GPS to verify it tho. On a good size hill they do bog Down quite abit. Its a heavy truck, and with all the BII in the tool boxes full of fuel and a truck in tow, don't plan on getting anywhere very soon.

 

[73m819]

Also check for sucking air leaks in the fuel lines and the change over valve.

 

[M35A2-AZ]

I love that video, I was in my M936 in the front and thinking it is going to be a long trip home.

I would check the fuel filter for sure and make sure the emergency shutoff is all the way open.
Also run some fuel treatment and good diesel in it.
Check for air leaks in the fuel lines, the fuel switch is a good place to look for leaks.

Good luck on the repairs.