I have a Mahindra 7520. I had to remove the fuel injection pump to fix a leaking gasket. This pump attaches to the pump gear with a key and a tapered shaft, so it is easy to re-assemble, as long as you don't spin the motor or the pump when they are separated. At least, that's what I thought.
When I reassembled it, it will hardly run, sputtering and coughing, spewing gray smoke. It's like the timing is off. The timing marks on the injection pump and the engine housing are aligned. In fact, in that position it won't run at all. When I loosen the pump and spin it clockwise, advancing the timing slightly, it will run some, but barely.
So, given it is a woodruff key reassembly, and I am positive the key went into the pump gear correctly (I used a mirror), the only way the timing could be off is if the pump gear itself somehow skipped a tooth. Maybe there was enough play when the pump is off that the gear could move to the side, disengaging from it's mating gear, and then re-align off one tooth. Is that possible?
When I reassembled it, it will hardly run, sputtering and coughing, spewing gray smoke. It's like the timing is off. The timing marks on the injection pump and the engine housing are aligned. In fact, in that position it won't run at all. When I loosen the pump and spin it clockwise, advancing the timing slightly, it will run some, but barely.
So, given it is a woodruff key reassembly, and I am positive the key went into the pump gear correctly (I used a mirror), the only way the timing could be off is if the pump gear itself somehow skipped a tooth. Maybe there was enough play when the pump is off that the gear could move to the side, disengaging from it's mating gear, and then re-align off one tooth. Is that possible?
Last edited: