Hey everyone, our fire company has a 1984, 5 ton M923A2 military truck that we got last year from military surplus. We use it for brush fires and other off road emergencies but we've only used it on maybe 20 calls so far (roughly put 2,000 miles on it). It has a Cummins NHC-250 engine in it but its very sluggish; been this way since we got it. We've spent a pile of money on new air/ fuel filters, fuel additives, and a throttle cable but nothing has changed its power. We're not looking into upgrading internal engine parts due to low finances, just possible "quick fixes." I've run both deuce and a halfs and 5 tons in the military so I know they aren't meant to blow the siding off of houses, however I've never driven one this sluggish. Multiple people I've talked to are telling me to take the muffler off and just straight pipe it. Im no mechanic but i know enough that it might add a little bit of power and lots of loud rumble, but that's the extent of it. Is this going to fix the sluggish problem or is their a bigger issue? Im open to any cheap suggestions on enhancing power or what to expect when I take the muffler off. Thanks!!!

 

i would check the fuel pump to make sure its putin out enough fuel for the injection pump to use...if i rember right the pump should be in the tank...if so take it out and turn it over ..if its not pumpin its because the shims fell out ...need to fish the tank and find all of them put back togther and dimpil the sides so it dont hapen again...scott

 

Ok thanks, I'll check that out first thing. Ill let you know what I find.