Diesel Electricity question

[BuzzyG]

Is there anything of an electrical nature on a diesel tractor that would affect the fuel output, idle speed, etc.

 

[V1Rotate]

I think you need to be more specific about what kind of problems you are having and what kind of tractor you have.

 

[Little_Grizzly]

Maybe.

 

[BuzzyG]

I have a runaway NH TC18 engine after having electrical problems, which turned out to be a burned out regulator.

I have the regulator replaced and everything seems to be operating well, except that the engine runs full out with no power and lots of black exhaust all the time. (Too much fuel to the cylinders???)

In my efforts to fix the problem, I have had the cam-driven injector pump off a couple of times, and did so again today thinking that perhaps I had stressed the linkage so that it could not work. When I put it back together, I checked the pump/solenoid pressure point, and it moved freely. After starting the engine with no improvement in operation, I removed the solenoid. The pump/solenoid pressure point on the back of the pump was fully depressed (in the off position) and would not return.

The engine cannot be stopped with the ignition switch, although the cut-off solenoid works when powered with 12v juice, something in the pump (or elsewhere) keeps the fuel supply to the engine from being affected by the solenoid. So I have to turn off the fuel and let it run down.

My thoughts about the electrical system possibly affecting fuel delivery is due to the fact that the problem began with a burned out regulator.

Any help would be appreciated.

 

[Rock knocker]

Is there anything of an electrical nature on a diesel tractor that would affect the fuel output, idle speed, etc.

In the old days, no. Diesel systems were completely mechanical, and once the starter motor had done it's job, all the electrical system was good for was the hour meter and the lights.

Modern systems have on board computers and any number of sensors. I would hazard a guess that your NH is new enough to have all the gizmo's, and as such, a voltage spike which got around the battery could have damaged something

 

[Jerry/MT]

I have a runaway NH TC18 engine after having electrical problems, which turned out to be a burned out regulator.

I have the regulator replaced and everything seems to be operating well, except that the engine runs full out with no power and lots of black exhaust all the time. (Too much fuel to the cylinders???)

In my efforts to fix the problem, I have had the cam-driven injector pump off a couple of times, and did so again today thinking that perhaps I had stressed the linkage so that it could not work. When I put it back together, I checked the pump/solenoid pressure point, and it moved freely. After starting the engine with no improvement in operation, I removed the solenoid. The pump/solenoid pressure point on the back of the pump was fully depressed (in the off position) and would not return.

The engine cannot be stopped with the ignition switch, although the cut-off solenoid works when powered with 12v juice, something in the pump (or elsewhere) keeps the fuel supply to the engine from being affected by the solenoid. So I have to turn off the fuel and let it run down.

My thoughts about the electrical system possibly affecting fuel delivery is due to the fact that the problem began with a burned out regulator.

Any help would be appreciated.

I think you have a hydromechanical injector pump with a solenoid shut off on your tractor in reading your post.

If that's true, then the only think electrical in your fuel delivery system is the shut off solenoid. If you can't shut the engine off with the key switch then your solenoid is "hot" all the time or had failed in the fully open position. To check, turn off the tank valve on the running engine and that should shut it down. If you don't have one, then remove the downstream line from the shutoff solenoid valve , or remove the solenoid valve itself it it's mounted on the pump and verify that it is closing.

There also appears to be something wrong with the throttle linkage or the injector pump itself (governor stuck?) since you don't appear to be able to to command lower rpm's. Are you sure you hooked the control linkage up properly when you removed the pump. Did you keep the pump timed when you reinstalled it? Dieseltech maybe able to help you with the pump issues.