Intermittent crank no start.

Been fighting the issue for a while now. I've put 4 CP3's on my 03 in the last 6 years. The first one the pump just physically failed and would not build pressure. The second one lasted a bit over 2 years (until the warranty was out on it) and then got a crank no start issue again. Pulled the line from the pump to the rail and cranked the engine over and zero fuel came out of the pump......my thoughts were, pump failed again. Got a Cummins reman through work this past Christmas and put it on and the truck fired right off without issue......two months later, same problem, crank no start so I took pump back off got it warranted at work. New pump installed and engine started just fine.

Injectors were redone at F1 back in 2015. I'm not ruling them out but I would think the problem I'm having would be ocurring more than just once every 2-3 months. Pump has no problem building 20-25k psi running the gears so I'm fairly certain the pump is not the issue. However, my ignition switch is pretty much done.....I can no longer turn it to acc. and if I leave the blower motor switch on after the engine is shutdown and key removed, the blower will sometimes come on randomly during the night and I get in the truck the next morning wondering how long the damn thing ran overnight. At this point, I'm wondering if my no start issue is electrical and not pump or injectors. Anyone else have this issue? Where else should I focus my search?

Forgot to mention, no codes when this happens either.......except for when i unplug the FCA trying to get engine to start.

Will it start on ether? I had a PR valve give similar symptoms.

Key switches are cheap, rule that out first.


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9 times out of 10 it starts without issue after about 3-4 revolutions. I'd hate to turn it into an ether baby. It's just that 1 time when it decides it doesn't want to start and you can crank on it until the cows come home. I put a PRV block off on the rail a while back to rule it out. Need to go ahead and change out the ignition switch to rule it out as well.

Still curious to know if a bad ignition switch would somehow keep the FCA from letting fuel go through it. The way my RP gauge is wired in I can't watch cranking RP.....only what the system is making after the engine is running. Once it's running there are no issues at all......mileage is still good, idle is super smooth, and it's not making any oil at all.

Unplugging the fuel control actuator (zero voltage) forces the pump to full flow. If it were to lose power, you've lost metering at your nozzles also.



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Have there been cases of this happening? I just don't know why this is so random in how it's happening......Surely if it's an ECM issue it would happen more often than it is.

To anyone who's replaced an ignition switch, isn't it a two piece item? Am I able to keep using the key I have or do I have to get a new key?

I believe a new key comes with the lock cylinder. Then you’ll have a different key for door locks and ignition.

Could this also be an intermittent failure in the crank position sensor? What does your rail pressure and fuel pressure read when the long crank happens?

The way my RP sensor is wired in it doesn't read while cranking.....when I had this happen back before this past Christmas, I borrowed a scanner from a co-worker and my rail was only reading less than 100psi.....replaced the pump and it fired up without issue. As for the possibility of a sensor failure, I would think a code would be thrown......I never have any codes when I check them. The crank and cam sensors have crossed my mind though......they're the factory pieces from '03.