John Deere 6630 series Injector fault
This is my first time writing here, I have a 6630 for a set of injectors, I installed 6 new Denso common rail injectors, it ran 5 minutes and then went out on cylinder number 1. I stopped the tractor and it did not start again, as the new injector was stuck, even with the injectors electrical wires disconnected, it was constantly injecting fuel into the number 1 cylinder. I removed the injector and got another one that was reinstalled and rebuilt, this time it ran for 4 hours in the workshop and has come back to do exactly the same. The same cylinder, the removed injector was sent to be disassembled and examined, no debris or particles found in the injector, all they said is that it was stuck, but I can’t see why ………. I’ve never posted here before but this job is getting to me and I can’t keep pulling injectors.
This is more than a long shot, but can you easily check if the intake and exhaust valves are opening and closing properly? I once fixed a six cylinder engine that had been slowly filling the crankcase with diesel for a year. The owner had replaced the head gasket himself and misplaced a tappet rod. An intake valve was not working but it was not easily noticeable as it would open a little in the vacuum. He had changed the lift pump and heater plugs twice, just as he had sealed the injector pump twice. He relocated the rod and never looked behind it! It’s highly unlikely it’s the valves but I was wondering if the exhaust valve was malfunctioning could the engine build enough pressure in the cylinder to mess up the injector shutoff? Just something unlikely to remove, if you can’t get to the valves easily running a compression test comparison with a pair of other cylinders would probably suffice instead.