I have a 2000 2500 4X4, 6 spd, with the 24valve cummins. no mods. It cranks but doesn't start. It happened once before. It cranked and cranked repeatedly. I intermittently waited for the starter to cool and after 10 min or so, when I tried again, it started on the first turn. It ran completely normal for a month. Now I drove it to work and then to lunch, after lunch it wont start it just spins away without a sputter. Any ideas on the troubleshooting steps?

thanks in advance
B

 

Fuel Pressure? Crank signal? Does the tach move?

 

Is your lift pump kicking initially with key to run? Is it as if you aren't getting fuel through the VP? If no codes, replace CKP.

 

Did you look for codes? If there's none then here's the basic's:

Is the VP getting fuel? If yes then how much?
Is the VP getting electricity?
Are the fuel system fuses and relays functional?
Is the crank sensor working? Possible code with this one if its not.

If yes to all then it should start.

 

FWIW, my CKP went out twice with no codes. 1st time I replaced with Cummins, 2nd time with lifetime Autozone trash. At least next time will be labor only.

 

You might look at this:
http://www.bluechipdiesel.com/vp44diagnostichelp.html
You can learn and TS all you need to know about your fuel system.
Good luck,
hhrumph

 

You might want to try loosening a couple of injector lines, then crank the engine to purge out any air. If this helps it to start, it will give you a direction to go in.

 

That trouble shooting graph is awesome. Like they said you need to know how much fuel the lift pump is putting out first thing.

If it has good pressure use the trouble shooting thread above and check the wiring to the VP if that's good I would say it is the VP.

I have a intermittent problem with mine. If you want to check after you have tracked it down to the VP you can disconnect the air heater spray a shot of either into intake and try to start without touching the fuel pedal. If it starts and goes to idle fine its the VP.

I learned this just recently diagnosing mine.

 

What is CKP?

I have the same problem as the original poster.
I have good fuel pressure after the lift pump.I had a new injection pump about a year ago (25k) and I have some issues with a speed sensor, I think. The tach bounces from actual RPM to 0 from time to time, and I have a loss of power. It's intermittent.

 

I changed out my crankshaft position sensor. Problem solved.

 

Crank Position Sensor located behind the starter. Disconnect batteries. Leave starter wires connected. Set starter on frame & install CKP. You need a 10mm 12pt combination wrench to remove starter bolts. I used a jack & 2/4 for leverage the 1st time because the bolts were tight.

Symptoms: Started fine the 1st time in the morning. Would intermittently not start foe example after going into a store & returning. Finally stopped starting completely. Lift pump process was normal. Starter cranked normal. No codes.

 

I just got around to looking at this. It started fine for a week or so. Then crank but no start. Tach didn't move at all. I tried again in an hour and it started and ran fine. I checked the codes and found po336. I replaced the CPS. I will let everyone know if that doesn't fix it. thanks for the advice.
B

 

See there. We've been broken down so many times we can skip the code reader.

 

I need help!!!!!! Where can i get a relay/harness assembly and a starter solenoid jumper?

 

Alec_sampson you're jumping into a very old thread and likely not to get the help you're after.

You can start a new thread about your problem or PM me and I'd be happy to help.