I acquired my 636 Pettibone a few years ago and it has become my favorite tool for my reclaimed lumber business. I am now retiring but keeping the 636 for personal use. Yesterday it stalled out and when I try starting it it will run for about 2 seconds and cut out again. I'm assuming its an electrical issue and its a sensor of some sort shutting down the engine. Where do I start in my trouble shooting process here?
Little 4 cylinder diesel or Detroit Diesel in it? Year and engine type is a big aid here.
If it's a diesel we don't even need to know which brand engine, just a photo of the injection pump matters most.
Detroit is a tad different. If has Murphy Switches or just typical solenoid system.
Thanks for responding. It's a 4 cylinder.
Little 4BT, the engine develop oil pressure pretty quick? That is a Auto Shut down style oil switch to the left of the fuel transfer pump, 3 wire. No broken wires?
Oil pressure goes up quickly. I'm not seeing any breaks in the wiring. It's overdue for an oil change so will do that. Is there a online site to order all filters for the 636? Would also like to acquire a service manual.
All need to order for if only doing Engine is 4BT Cummins search. If need chassis hydraulic and or Pettibone installed Air Cleaner then would either have to order by existing p/n or go to a Online Filter source and see if have Off Highway Application Listings. Fleabay may be the best choice for your manual.
Thanks for the info. I'll keep troubleshooting the shutoff issue.
To me(not having worked B series cummins) appears a shut down solenoid on top of pump? Should have power key on if not on a shut down system, if is a auto stop system should energize on crank and if power stops then something in shutdown system problem If maintains power and dies could be fuel supply or internal pump issue.
It is a Fuel Shut off Solenoid, Found this online Cummins 4BT - Electrical Shut Off Valves - Diesel Engines Troubleshooting (dieselmechanic.info)
A clogged fuel return line is a very common cause of running a second and stopping. Try taking the fitting the return line goes to out of the top of the pump, if it runs without it, your problem is there somewhere. Take the fitting out, not the line off the fitting, because the fittings are a common place for a clog. I don't know if that pump has the fiber coupler that sheds black granules or not, but that will glog that fitting.
Robert Bosch VE Series, uncertain the fault issues of these.
I appreciate the input, I'll try again Monday morning.
Michael did you find out what's going on? I think i have the same problem. I bought a non runner 4bta. The seller said it would run for two seconds and quit. He got frustrated so he put it up for sale. I haven't tried it for lack of adapter/flywheel/starter which I have sourced since, I need a starter spacer still.
Did you check out the link in Dmiller's post #12? it has ohm specs for the shut off coil, and the bottom picture shows how to remove the plunger to disable the shutoff for testing purposes, after you've checked the voltage supplied, and checked the ohms before and AFTER starting it. Actually check that the lift pump is producing decent flow and pressure first, fuel supply is always the #1 thing to check with any injection pump.
I just checked ohms. I got 10.7. I have a Bosch VE as shown in the first diagram.
The lift pump is currently loose and so are the lines. I am thinking once I have the means to spin the engine over, I'm missing a starter spacer, I could check the lift pump, compression etc.
I had to make an unexpected trip out of town but now I'm back to my project. I checked the fuel lines and they are clear. I was able to jump the fuel shutoff valve to get the machine running hoping to move it into my shop. But now I can't move it forward or back. The steering works along with the boom, but somehow I did something to lock it up. I'm thinking it has to be an electronic issue.
Sounds as a main power relay or circuit has a fault, maybe a cannon plug along a harness corroded too far, when find it will be mad that missed it.
I have checked all connections and all looks good. How do I test power relays?
First is validate ohms across solenoid, should be a main power relay, appearance will be like a starter solenoid may have a circuit breaker and can be up or downstream of the solenoid. check for power across and see if that disrupts upon starting as well power at fuel solenoid, if there when start but drops as is running. Early auto shut down systems had a bypass to start on, then would rely upon continuity across a N/C coolant and a N/O oil pressure switch. Would be a bypass from cranking side of start circuit that provided power to run the engine. As described as are bypassing the run circuit and have no control power I fall back to main power supply to those controls. That just requires validating voltage available key or switch on, then back checking until find where power is or is not.
Now that you've narrowed it down to an electrical issue, if you don't understand electrical troubleshooting, it's hard to describe in words. You need three things, youtube, a wiring diagram, and a Powerprobe.
I ended up doing it the old fashion way by tracing each wire to it's destination. Finally found the short and I am now up and running again. Gave me a chance to get to know the machine a little better and gave it a good cleaning while I was at it. Thanks for all your input.