Fuel system issues on NH T4.75

[DbyC]

2014 New Holland T4.75

Last week, I got a 3808 fault code. I was 50 hrs shy of a fuel filter service, so I changed them out and checked the prefilter. After replacing the filters, it ran good for about an hour and then gave me a 3293 fault code. Both codes are related to the fuel metering unit, which I guess is some type of solenoid valve.

If I cut it off and on a few times, the 3293 fault goes away but comes back after another hour of running.

Can anybody provide further troubleshooting guidance?

Otherwise, I'll haul it to the tractor shop early next week.


Thanks.

 

[Bavarian]

If your engine has a common rail fuel system, and the code says something similar to "low rail prssure", then there is the possibility of a problem with the fuel supply solenoid.
I had one fail on a John Deere. The dealer walked me through the process.
First step, check for sufficient fuel flow to the pump.
Then they had me to replace the pressure sensor on the fuel rail. Didn't solve the problem.
Next step was to replace the fill solenoid including the pressure control valve.
That finally solved my problem.

It's very likely that Green and Blue use the same manufacturer of the common rail system. The symptoms of failure can be similar across the brands.

 

[DbyC]

Thanks for the reply.

From what I have found on the codes:
3808 - fuel metering unit: setpoint of metering unit in idle mode not plausible
3293 - fuel metering unit: maximum positive deviation of the rail pressure exceeded