Engine Mechanical problem
2002 GMC Truck 6 cyl Four Wheel Drive Automatic 90000 miles
engine will not start turns over but tries then kind of backfires sometimes. Had a one code set p0122 which we replace trottle position sensor. Does the same thing. Took feul filter off to check for feul. Fuel pump is coming on. Dont know what else to ck any help thanks
You need to check the fuel pressure, not just see if fuel is coming out of the line. See if it will start and run if you spray some starting fluid to it. Check the fuel filter, and the fuel pressure regulator, also check the relay for the pump.