I have a 2015 Mahindra 2638L that cranks over but does not try to start. Have fuel going up to the injectors and have made sure there is no air in the lines. If using a little gasoline on a rag over the intake, the tractor fires and runs until the gasoline is gone. Otherwise it does not try to do anything. I checked everything I could, cleaned all the grounds and made sure I have a good ground at the ECU. Little more history. This tractor sat for a few weeks and when we tried starting it, it would not start. Just clicked. Some troubleshooting led me to find that the 12+ line going to the ECU had a bad connector close to the battery. Repaired the connector and from that point, the engine would turn over, but not try firing.