P0306 Chevrolet -

Question

99 Gmc Suburban,5.7l Vortec. tripping P0306 code only. Replaced plugs, wires, cap and rotor, distributor, and injectors, in that order. took it in to the dealership because all this did not fix it. they told my #6 cylinder had a bad head. I replaced both heads and still have a p0360 code. compreession is in the middle of all the cylinders. when reset it runns good and strong for 30 seconds to 4 miniute ( random) before resetting. still having problems any help would be apreciated.

Answer 1

Do a leak down test on the cylinder. leak down test performs better than just doing a compression test . This will rule out a mechancical condition as being at fault.On this type of engine it may be possible that injector connector  # 6 and #8 can get crossed