Cummins PT pump Diagnostics

[simp5782]

attached.

Mods please make as a sticky as it would help.

 

[WillWagner]

This applies to basically ALL Cummins PT pumps, AFC or non AFC. If the pump you are working on does not have an AFC....non turbocharged engine....skip over the parts that relate to AFC operation. Thanks Simp, good find! And, this is directly from the Cummins troubleshooting steps.

 

[WillWagner]

AND, what the attached does not mention, IF you think you have a pump/engine issue, divide the system in half, engine/truck, by ELIMINATING the chassis. If the engine runs/accelerates fine with a line directly from the engine into a clean bucket of go juice, the issue is on the chassis. Keep in mind, if air is introduced into a PT system, it takes a few...10-15 mins of running...to purge the air from the system. Start it, throttleit a few times and shut it off, let it sit an hour. If it re-starts and runs 1/2 way normal upon re start, the issue is on the chassis.

 

[Micmada]

I have a fueler with a 6CT and PTO and after 5 - 10 min it shuts down. Will restart but shuts down immediately. If I let it rest 20 min, it runs 5-10 min and then shuts down doing the same thing.

I tied the fuel shutoff valve open and the thing runs great, no apparent issues. Seems like a safety feature is tripping. I was worried it was overheating but no physical signs of it so far.

 

[WillWagner]

The FSOV's used on the midrange engines, especially the older one, I forget if it was the Trombetta that was replaces with Synchro Start or the other way around, did have a tendency burn up coils. SOMEWHERE here there resistance values posted for them. When it shuts off, take a resistance reading, or, if you don't care, just rig up a "pull to shut down" cable. Not a safety feature, a failed part