I have an 5.9L NA in a sprayer (same basic 12v that's in my 95 dodge without the turbo) and it's a little hard to start even with 2 large ag batteries when it's above 50F, then almost impossible when it's below freezing, and won't start at all when it's been shut off after being warmed up. I noticed similiar problems noted in other posts and one response pointed to the injectors and/or pump.

I was told the engine may have been rebuilt when I bought the sprayer - sometimes I think that's just the standard line salesmen use. I wonder however, if there had been work, the pump timing could be off. Is setting the pump timing is difficult on the 5.9L? On other engines it seems the pump only goes in one way (shaft is keyed) - is the 5.9L like this?

I've had injector problems on a cat engine before (I bought it that way), but it started fine and the only problem was low power. Would injector problems on the cummins 5.9 cause hard starting/hot starting problems?

Thank you very much,

Pat Harmet

 

A bad injector that doesn't seal off back pressure can force air from the compression stroke back into the return fuel line as the engine is shut down and fuel injection ceases. This air can cause the pump to airlock on the next start.
Remove the injectors and have them tested. I have mine done at the local JD dealer.

On the 12 valve the pump shaft is tapered, not keyed. Moving the gear on the shaft is how timing is changed.