I have a 2003 5.9 Cummins with 177,000 miles, everything is stock to my knowledge, generally I turn the key and it fires within a couple seconds. Recently the last 4 times I've turned the key it takes anywhere from 5-8 seconds before it fires, I replaced the fuel filter and it fired right up as normal, after 3 days with a new fuel filter I am back to the longer startup then normal. Any ideas ? I have ran some diesel Klean though it in this past month.

 

Did you fuel up somewhere out of the norm? It seems like maybe you got a bad batch or some water in there- how's it running once started? Any excessive smoke at start up or while driving?

 

Sign of injectors wearing. Mine has 220k. Talked with the guys at OFI and they told me that long cranking times are due to check valve to fuel bypass and not hold pressure sufficient for injection event. I am in the same boat. Just waiting to clear my plate and do a major upgrade.

 

What is your FP and RP when cranking?

 

my buddies 04 did the same thing we installed a fass fuel system now it starts better than it ever has. he still needs to replace his injectors someday