Cummings 8.3 Idle problems

I am having some idle issues with our unit - it is a 8.3 cummings (fly-by-wire I believe).

Sometimes the idle runs from 900 to 1000 rpm and this causes a problem shifting into gear. I find if I bump the pedal it sometimes helps and then again sometimes it does not help.

My allison transmission simply will not shift into any gear with rpm above 850.

Thoughts and anyone having this issue and the solution would be helpful.

Thanks in advance!

Bill & Judy
Cummings 8.3 Idle problems

Couple areas to look at, first is the return spring at the fuel rack, the other and most likely the answer is the throttle cable is dry in the cable housing. Some throttle cables have a method of greasing them.
Cummings 8.3 Idle problems

Thank you for the input. I was finally able to talk to Cummings and the guy there advised it would be one of possibly 3 things. My unit has the Bosch injector pump and that is connected to the throttle by a remote (fly-by-wire) which is connected by a small chain type connection. For some this chain is not releasing when the foot pedal is relaxed. The second thing is the unit is also connected by a small cable to the allison transmission and this link may not be relaxing enough. The 3rd is the foot pedal itself.

Should be interesting with cold weather coming on - may have to wait for spring.

My other option is: This spring I am taking the unit to my injector shop for new injectors and they are going to crank in about 50 more ponies at that time. I have a feeling they will be more than happy to resolve this issue at the same time.

God Bless - Bill & Judy