96 Vortec Misfiring

Hey guys my truck is really getting to me now it runs a bit rough but seem's to idle nice. I've changed plugs,wires can & rotor seemed to get a little better but is still misfiring. The engine light does not come on but after about 10-15 minutes of driving it starts to flash. The last time I had my hands on a scanner it said I have a misfire in cyclinders 3 and 6. What would cause these two cylinders to misfire? What should I check??

Hey guys my truck is really getting to me now it runs a bit rough but seem's to idle nice. I've changed plugs,wires can & rotor seemed to get a little better but is still misfiring. The engine light does not come on but after about 10-15 minutes of driving it starts to flash. The last time I had my hands on a scanner it said I have a misfire in cyclinders 3 and 6. What would cause these two cylinders to misfire? What should I check??

look to see if the wires are crossed, the injectors could be cloging. or you have bad fuel.

If triple checked the wires and pumped about $20 of fresh fuel in, I will swap out the injectors for different ones, can I clean the old injectors with brake cleaner or anything?? If the cats are clogged would it cause this?

Another area to check is the distributor gear may be worn. To check this pull the cap and gently try to rotate the rotor back and forth. The book say there is no rotational play allowed.

I realized I can't check or clean the injector's without taking apart the intake manifold so scratch that idea lol. Can the dist. drive gear actually make it run off?? I read on this before, my gear seem's to be a bit worn it does have grooves in it. I grabbed another dist. from the wreckers that has a better gear on it I'll put it in and see how goes

Problem solved!! The motor I bought from the wreckers was garbage, got another one within warranty time! Dropped it in and runs mint, thanks for all the help guys.

Ps: They wreckers wouldn't believe me that the motor was bad so they made me drive it to them and on the way the motor lost oil pressure and started knocking real hard. It seized one exit away. Does anyone know what the problem with the old motor was??