Okay so i got off work early and decided to pb blaster a frozen spark plug. Well after getting that out and installing the new one i checked the rotor to see if it had ever been replaced nope so i cleaned off the corrosion to go down to the parts store. cleared the pcm to get rid of evap code. fired it up and blam it now sounds like my truck bred with a 12 gauge lol. Also i tinkered with a repaired injector wire (mouse damage from sitting) to see if aamco had used a connector or not. So im thinking new cap rotor wires to see if its a simple fix. if that doesnt solve it possibly a leaking and/or misfiring injector?

 

forgot to mention its 02 qc 1500 with a 5.9

 

bump/ if i disconnect the injector on #2 it stops.....

 

Update: ignition tune up parts no change, checked spark. All seems well so im thinking either injector or valve?

 

Do you get a CEL? Have vodes read - stored codes. Should show which cylinder had the misfire.

Might try to move suspect injector to another cylinder and see if problem moves.

 

If you are backfiring....... that implies a valve is still open when the plug fires. I would take a look at plug wire routing, make sure you have the firing order correct. If all that looks good, do a compression test on the cylinder in question....... possibly a valve sticking open.

 

Also, how many miles on truck? Is the oil clean or cruddy? This could be a contributing factor in valves sticking. Also if timing set is very worn, it would effect valve tming.

If you put your truck info in your sig it would help us help you....