Crank but no start

[DLGonzo]

2008 2500 automatic with smarty jr delete 150,000 miles

will not start. It will crank for a couple seconds stop for a second then crank again. Crank is strong but no fire. Had several misfire codes and a cam/crank sensor code. Cleared codes and still no start. Sounds like an electrical/computer issue to me but don’t know where to start.

 

[Darkbloodmon]

Have you installed or changed anything since your starting issues began?

A code readout could help add some more information to work with.

FWIW, the cam sensor is primary on start up and a secondary failsafe once the engine is running. Here is a link to a recent post about a similar issue.

 

[Timd32]

Seems like a good place to start as any.

Here is what I found on that.

There is another document that goes into some other stuff, but I don't see any reference to the CAM sensor in that list.

 

[p-Bar]

unload any boxes you may have.

 

[jghflys]

Check batteries and x-over cables for low voltages and bad connections.

 

[PMalin]

I have a 2001.5, if the battery voltage is low, it will still crank the engine over, but it wont start. The Injector pump and electronics seem to not work at some voltage below some threshold, yet it will still crank over. I would put a digital voltmeter across the battery terminals and (use the min max function if it has it) and test for the dip in voltage when it is cranking. I think if it goes below 10.8 volts it's time for new batteries. However if your thowing position sensor codes that would be of concern that needs addressed. Obviously start with replacing a cheap sensor, or look for wire damage from critters under the hood, dont just jump in the high price computer modules off the bat.

 

[DLGonzo]

Getting code P0336 and P0335. Pulled crank sensor and cleaned it. Still no start. Guess I’ll go pick up a new crank sensor.

 

[Timd32]

Just a warning sometimes these have you chasing your tail, but here is some info on those codes that's listed.

I try to look at the simple stuff first. And see if they have common things in the paperwork.

Had to rename these so the number means nothing related to the actual code.

 

[DLGonzo]

Crankshaft sensor did test bad. Replacing the sensor fixed the problem. O’reilly’s had it in stock.

 

[BigPapa]

You’ll be wanting to get a Cummins sensor.

 

[Darkbloodmon]

I agree on the OEM sensor. From experience in retail automotive if I can't get an OEM sensor at a decent price and relatively quickly; the WVE and NTK brands are my go to, I don't have much faith in the house branded electronics.

I looked into this recently and found out that the cam and crank sensor are the same fit form and function, another way to test a bad sensor in a pinch would be swaping the two like a coil pack. The cam sensor is under the injection pump not as easy too get to but do-able with patience.