did head gaskets, someone swapped the cams on me and i failed to realise this prior to install and turning it over, broke the 4 rocker arms on the intake valves on left side, replaced them, swapped cams, timed to factory specs, now the engine turns over great but after 10 seconds or so it will back fire once very slightly out of the intake, could this be a possible bent valve or do i still need to adjust the timing more?

 

i have fuel, i have spark, all connections are hooked up, i have power going through all connections, tested the knock sensor, the crank sensor, and the cam sensor, no codes have been throwen, i have excelent fuel rail pressure good fuel spray out of the injectors and the plugs spark like brand new

 

If you were able to run a compression test ,it could eliminate a lot of questions. Can you do this?