I have a thundercat that wont start. It ran fine last time using it but then it didnt want to start and when i got it to run it was backfiring alot and had no power. Finally wouldn't start. I dumped the fuel tank and put new fuel. Replaced the spark plugs and verified good spark. Ohm out wires and coil both in spec. Pulled inj both are spraying. Replaced the fuel filter. Readjusted TPS and set idle speed control. Atv still wont start but i can get it to run using starter fluid but wont stay running. Im thinking it might be a MAP or ISC but not sure how to test. Any ideas???