Cummins Celect N14 engine sudden failure to start.

foxy farmer

My contractors JD 6950 harvester has a Cummins Celect N14 engine 6 cylinder common rail. It had been starting on the button up till yesterday but today will only swing but not fire. No puff of smoke from the exhaust.
The fuel filters are all fine clean and checked. The injector pump will pump plenty fuel when cranking so not likely a fueling issue. Batteries are ok too. If a sensor packed up would it prevent the engine from starting and if so which one might be the most likely culprit?

Desolation Of Smug

foxy farmer wrote: »

My contractors JD 6950 harvester has a Cummins Celect N14 engine 6 cylinder common rail. It had been starting on the button up till yesterday but today will only swing but not fire. No puff of smoke from the exhaust.
The fuel filters are all fine clean and checked. The injector pump will pump plenty fuel when cranking so not likely a fueling issue. Batteries are ok too. If a sensor packed up would it prevent the engine from starting and if so which one might be the most likely culprit?

Crank or cam sensor? - if the engines ecu doesn't know what position either is at, it won't start. I'd look there first then start looking for broken wires. Any codes showing?

foxy farmer

Desolation Of Smug wrote: »

Crank or cam sensor? - if the engines ecu doesn't know what position either is at, it won't start. I'd look there first then start looking for broken wires. Any codes showing?

The machine shows no codes only warning lights for various faults. Nothing out of the ordinary lighting.
Looking on You Tube these engines are common on artics in the States. They suggest that there is one position sensor that fails regularly which would prevent engine from starting so what you're suggesting is probably on the ball.
JD main dealers are of little help as its not a JD engine and don't keep much for them. They got a contact for Cummins in Dublin last night so should know more today.

Desolation Of Smug

foxy farmer wrote: »

The machine shows no codes only warning lights for various faults. Nothing out of the ordinary lighting.
Looking on You Tube these engines are common on artics in the States. They suggest that there is one position sensor that fails regularly which would prevent engine from starting so what you're suggesting is probably on the ball.
JD main dealers are of little help as its not a JD engine and don't keep much for them. They got a contact for Cummins in Dublin last night so should know more today.

Try removing the connectors to the sensors first, clean them with contact cleaner spray and re-connect - might be a poor circuit. If that doesn't work, they're both Hall effect sensors, so pull them out and check that the tips aren't in any way damaged - if they are, they're toast. They can also go bad internally, you can check that they're providing a pulsed output as you crank the engine using a multi-meter through the insulation as someone turns it over on the key. I can't remember the output voltage strength, but it's usually small enough and should be pulsed. If they're gone bad, they'll either be open circuit or full resistance - check using the continuity and Ohms functions on your multimeter. Make sure you're testing the output wire and not the input btw.

Desolation Of Smug

Also -I asked a mate - btw, the stop solenoids give bother in these too - usually an in line fuse issue on the harness, sets no codes and engine won't start - check all fuses carefully.

Man of Aran

Desolation Of Smug wrote: »

Also -I asked a mate - btw, the stop solenoids give bother in these too - usually an in line fuse issue on the harness, sets no codes and engine won't start - check all fuses carefully.

Yep, as Sherlock said once, check the elementary stuff first Dr Watson!

Foxy said it was working fine on 3rd Mar but won't start on 4th.
Anybody doing any other work on the machine may have disturbed some fundamental things like connection blocks , terminals , earth straps and of course blown some basic but essential fuse.
Always retrace your / technician's previous steps or actions taken when seemingly puzzling cases like this happen.

bren11

I dont know if this is of any help but it is vacuum / breather problem on a cummins b series. If not maybe someone on this forum can help;

http://farmingforum.co.uk/forums/showthread.php?21033-Jcb-fastrac-185-65-fuel-problem

foxy farmer

Position sensor located behind oil pump under injector pump was in trouble. In a right awkward spot. Open ended 17mm spanner had to be bent at 90* and ground down to get in there to open it. Replaced and away she went. The stop solenoid had been replaced over 4 yrs ago. Apparently its recommended that the sensors and stop solenoid be replaced every 5 yrs regardless..
Anyway these things are better happening now than in the middle of first cut. One less thing to worry about when it's out at grass.