Hello, I have a older model ZD21 with 150 hours (has been sitting for several years. Started and ran fine, even with the old fuel and no service, but then I had it runnning and I accidentaly lifted the arms up without the parking brake engaged the mower shut off. Then would not restrart, I drained all old fuel, changed the fuel filters, and ensured no air in the system. Fuel makes it all the way to the last hose, before the injectors, but when I loosened the injectors no fuel at all??????? Any suggestions would help