BX1870 strange starting issue

[Dave M7040]

So it isn't really a true runaway. It revs itself up, but will sometimes shut down with the key on the first time, sometimes I have to quickly cycle the key on/off, and it shuts off that time. So far, it is 100% for shutting down on the first or second try. But yeah, a true runaway ends in a large repair bill!


My gut feeling is that it isn't crankcase oil, but something like a stuck fuel injector dumping fuel. The more I'm typing on this thread, the more I'm thinking it is possibly moisture in the fuel. For some reason it isn't gelling, but causing havoc in an injectors, sometimes...

An injector will not fail in a way to cause unintended acceleration. The injection pump having s stuck rack (older design) can do it. I do not know how common rail new tractor systems fail.

Dave

 

[David_Kb7uns]

Would not think a BX is common rail now but still the regular injector pump. I would be looking at the injection pump/governor/shutoff lever area.
David

 

[SPYDERLK]

So it isn't really a true runaway. It revs itself up, but will sometimes shut down with the key on the first time, sometimes I have to quickly cycle the key on/off, and it shuts off that time. So far, it is 100% for shutting down on the first or second try. But yeah, a true runaway ends in a large repair bill!


My gut feeling is that it isn't crankcase oil, but something like a stuck fuel injector dumping fuel. The more I'm typing on this thread, the more I'm thinking it is possibly moisture in the fuel. For some reason it isn't gelling, but causing havoc in an injectors, sometimes...

I think the fueling control for your injector pump is sticking in full fueled condition. Essentially the function that provides more fuel to maintain RPM selected by your hand throttle setting. When you turn off the engine the RPM falls waa-ay below the throttle setting and more fuel is automatically called for -- But not available due the shut solenoid. So, then later you start with the full fuel command in effect and stuck there because of cold.

Lubricative fuel additives may straighten this out.​

 

[dodge man]

I think the fueling control for your injector pump is sticking in full fueled condition. Essentially the function that provides more fuel to maintain RPM selected by your hand throttle setting. When you turn off the engine the RPM falls waa-ay below the throttle setting and more fuel is automatically called for -- But not available due the shut solenoid. So, then later you start with the full fuel command in effect and stuck there because of cold.

Lubricative fuel additives may straighten this out.​

I tend to agree with this, could also be the governor is hanging up and calling for more fuel.

 

[SPYDERLK]

I tend to agree with this, could also be the governor is hanging up and calling for more fuel.

Yeah, like a governor. But I dont know what they call it on a diesel. :confused3:

 

[dodge man]

They call it a governor believe or not.

 

[smokingcrater]

I think the fueling control for your injector pump is sticking in full fueled condition. Essentially the function that provides more fuel to maintain RPM selected by your hand throttle setting. When you turn off the engine the RPM falls waa-ay below the throttle setting and more fuel is automatically called for -- But not available due the shut solenoid. So, then later you start with the full fuel command in effect and stuck there because of cold.

Lubricative fuel additives may straighten this out.​

That seems to fit the symptoms exactly. That could also explain the no-start after it does this. After it revs way up, the governor decides to cut as much fuel as possible, and essentially shuts it off entirely.

Just tried starting again today (30some degrees out), and it was fine. Definitely happens in cold weather only.