Hey Everyone. Got a 863 the wont fire back up after a shut down. Machine fires up and runs perfect but turn the machine off than right back on and it wont fire. You let the machine sit for an hour and it fires up. I bought the machine with that problem known, pervious owner had replaced the fuel shutoff solenoid. Didn't fix the issue. I put the factory shut off solenoid in and it still didn't fix the issue. 1800 hours on machine. Appreciate any input.
Assuming you mean it will turn over but not fire up?
Yes. Turns over but doesn't fire up
Well, you need fuel, air and compression to start. What do the air filters look like and don’t be afraid to try and spray some WD-40 through the air canister, with the inner element out and see what happens. How has the maintenance been on it? What motor is in it? Does it turn over strong? Try a jump pack or a boost and see what happens?
Everything maintenance wise is good. The machine fires up great when you first start it and has ran for 3 hours straight multiple times with plenty of power. But when you turn the machine off, and try and turn it right back on it doesn't fire up. It cranks strong but doesn't fire up. I think Its not sending voltage or not sending enough voltage to the shutoff solenoid to open the fuel back up. Trying to figure out why. I know theres a sequence of safetys it has to prove before it gets to the shut off solenoid. Is there a diagram of that somewhere or ladder diagram of the path the circuit takes?
Could very well be that once the wiring gets hot it cannot carry the current any more. It is just like a 10 gauge wire, it can carry 50 amps all day at minus 40 C but can only carry 30 amps at full engine temperature when confined and heated up and that is only if the cable is 100 percent good with no weak spots or overheated areas. I would check the wire that feeds the fuel solenoid from the source to the solenoid with it disconnected and running a 5-10 amp bulb. If it can do it while hot it is not a wiring issue with the solenoid. Could be a relay dropping out when hot, I made some testers to be able to pull relays out and get access to the pins to test for voltage loss. Some key switches sometimes drop out once running for a long time, but your seems to crank but could be tested to rule out if the Accesory terminal is dropping out. Testing is cheaper than firing the parts cannon. Simon C
Forgot to say that the Ignition terminal of key could be tested also. Simon C
Thanks for input. I will check the wire itself tomorrow.
Since it starts and runs fine cold but won't restart until it sits, I'd be looking at a heat-related electrical issue before anything else. Could be a relay, ignition switch, wiring connection, or the fuel shutoff circuit acting up when hot. Next time it won't start, check if the shutoff solenoid is getting power and whether you're getting fuel while cranking. If you're chasing an intermittent electrical problem, the wiring diagrams and troubleshooting section in the service manual can be really helpful. You can use this one: https://manualsshop.com/products/bo...er-loader-repair-service-manual-instant-pdf-1
Ill take a look at that. It also does this issue cold restarting. You fire the machine up for the first time that day, and shut it down immediately and than it just will crank no start even with the machine cold.
I would say you have a positive or negative wire that is compromised or switch that is only good for one start. Simon C
Nice! I will definitely start looking in that direction tonight. Will update with anything i find.
What does the exhaust look like, when it restarts?
Clean. No excess smoke
Okay, was thinking an injector may be leaking. Have you tried the WD-40 with the filters out? I would be trying to prove its not an electrical or safety, keeping the engine from starting. Do you have any codes or idiot lights? Maybe an oil pressure or temp sender having to cool down or clean itself off?
Something to note here, the Bobcat 863 was fitted with the Deutz BF4M1011F. All the wiring for the engine goes through a rectangle plug, be sure and check that plug connection, especially the terminals of that plug. Also, remove the air box cover to view the wires inside the air box, they're bad about deteriorating in the heat inside that air box.
Good to put in my archives. Simon C