Mike Mc

After traveling 1,250 mi to visit my mother in Seeley Lake, Mt we headed to the north entrance of Yellowstone. At the entrance pay booth the man commented that my truck idled really really loud. I rolled my eyes back (sun glasses on) paid the $25 entrance fee and with a quick roll on the throttle I left him some good black diesel smoke. That ought to bring a smile to his face. LoL

As we start climbing the 8-10% grades I'm a little nervous that my drive train is going to fail pulling the 25,000 load up these steep hills. With the engine running 2,100 and making 25psi of boost, automatic in 2nd gear and torque converter locked via toggle switch. The brownie in under with the Dana 80 rear end having 5:38 gears we climbed the grades at 19mph. Sometimes I felt that I needed to down shift the auto to first gear cuz the cummins was running out of power but then the torque converter won't lock up and the tranny gets hot real quick. But it made it up and over.

The Pac Brake works better than I expected for holding the load back coming down hills. It sure does pump out a lot of white/grey smoke out the stack descending at about 2,000 rpm. On the long down grades it seems to back fire after the brake is shut off and go pedal applied. Although it would pump out grey smoke before the Pac brake was installed if I came down the hills at higher rpm's.

Any ideas why I get so much grey smoke and back fire on long down hills?

bannerd

What type of transmission?

That truck is a beast, how heavy is it alone?

Mike Mc

b, the truck full of fluids no cargo or passengers weights 10,200lbs.

I did have a Fuller 610 ten speed tranny but now it's a '94-'95 47RH with all the goodies.

Mike Mc

The '93 5.9 is getting a little rough starting in the mornings and smoke a lot. It seems to run good once fully warmed up. I searched and read the problem most likely is the injectors. If the injectors need to be replaced I would like to get more HP for hauling this heavy load.

In the sticky I read using the 9mm injector is a good upgrade for the non IC engine. What would you all recommend the same injector for the '93 with a Superduty intercooler? What kind of HP increase might be gained from using the bigger injectors?

bannerd

This is a tough call.. if you increase the injectors you're putting more stress on the engine (heat wise) going up steep grades. Big trucks have massive amount of gears so the engine is not killing itself. The 10 speed Eaton would have climbed the hill because of the small gear ratios. Unless it was a manual then that would be a lot of work

I'm not sure what would be the best advice here.. if you climb grades like that once every year, then I would leave it alone. If you do it all the time hauling loads.. then the drive train will need some serious thinking.

dodgenstein

9mm is the diameter of the injector tip. Intercooled injectors have a 7mm tip, so they are not interchangeable into a 93 motor. There are adapters to go the other way though (7mm in non-intercooled).