Posted by David Sherman on Saturday, September 03, 2005 at 4:57AM :
I am about at my wit's end with my JD 2010 diesel tractor/backhoe/loader. Even after overhauling the engine (new pistons, rings, liners, and bearings) it is very hard to start, doesn't fire on all cylinders until it's chugged along for several minutes on 2 or 3, has barely enough power to haul itself 100 yards up a 15% grade. All of this I could probably live with, but with any load at all, either driving uphill or doing some digging, it overheats. I have backflushed the block and radiator and put radiator cleaner in it. The water pump is fine. It has a new thermostat, but it overheats even with no thermostat at all. The injector pump and injectors were rebuilt several years ago and I haven't used it much since.
I've come to the conclusion that it must be out of time. When I re-assembled the engine I followed the manual's directions carefully for installing the oil pump correctly, which drives the stanadyne distributor-style injector pump. The injector pump has a tang that fits in a slot in the top of the oil pump shaft. When I put it all together the timing mark on the injector pump was where it should be when the flywheel (which has the timing mark on this engine) was at the TDC position. There is a punch mark on the injector pump shaft and oil pump shaft to mark how they should be installed. When I put it all together, it would barely run, and then only if I kept encouraging it with small shots of ether. I took the injector pump off and turned its shaft 180 degrees (the slot and tang are centered on their shafts), after which it ran considerably better and would at least fire on all cylinders after warming up.
My question is this: since all the timing marks are set like it shows in the manual, how can I determine, independent of timing marks whether the injector pump is timed right. If it was a gas engine, I'd look to see where the rotor was pointing, but I can't see how to do anything like that on a diesel. I figure I'll have to pull the oil pan to try moving the oil pump one tooth over, so I can verify that #1 piston really is up when the "TDC" mark on the flywheel is aligned. I can put my finger over the glow plug hole to make sure #1 is up on its compression stroke. What I don't know how to do is figure out the injector pump timing. At this point, I'd like to approach it like I don't believe anything in the manual, nor any marks on engine parts, but I need to get the injection timed right. Any ideas?
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