I have a 2005 Lull 944e-42 with the cummins engine. Sometimes the throttle stops responding. I can put it to the floor and the engine just keeps idling. I pump it a few times which may or may not help. At some point it just kicks in and starts responding like normal. I normally notice when going in reverse, but switching to forward won't fix it. When the pedal is down and not revving, I do think I'm hearing a pump sound...like a whoot, whoot whoot. Like an old fashion fireplace bellow/stoker is being pumped. I don't notice it when things are working. Of course, the engine is louder too. The only other thing I have noticed is its running a little hot. Fluids check out ok. My first step will be to replace most filters including fuel, air and hydraulic fluid. I just ordered the "1000 hour filter kit". But in case that doesn't work, what else should I look for?
Were you able to solve your issue? I have an older model 844TT highlander that has similar issues. When this happens it also makes it to where the unit will no move at all. I’ve tried pumping the pedal, but it doesn’t seem to help. After a few minutes the unit seems to build up enough pressure to get the tires rolling again. Unfortunately it seems to happen with mine regularly.
No, but I just recently got the Cummins insite to read the fault codes. I'm getting a 0368 which means the fuel injector is not able to deliver enough pressure so it's down rating. I've replaced all the filters and have the lift pump in order. I hope that's it and not the Bosch injector because that unit is 2k by itself. The code does clear after a few minutes of warming up, so I'm not sure why that would be caused by a failed pump. But it's my first step.