some diagnostic help please

put the truck back together with new denso plugs and new denso coils and wires. drove it and the miss changed in sound and style, but still missing. drove a bit close to home to get it warmed up. the scan gauge was great with the trans temps and the water temps. trans temp topped around 122F. water topped at 184.

the miss was making the engine move, but not as bad as before, but not usable yet either. it finally coded p0303, random miss cylinder 3, which, according to lots of discussions i've read, often can't code the actual problem. the different thing is that this time the MIL never went on.

topside under the hood there was a "snapping" sound, as if there was a stray spark outside of the covers. perhaps i broke the ceramic.... has anyone ever heard this? when i take it apart i will search for shorts with the electrical meter. i really dislike this ignition setup. the engines i learned on, you just shorted the plugs with a screwdriver and Presto!, there's the problem...

I suspect that this miss is a fuel injector. still on plan A, i am going to get down to the fuel rails and replace all the injectors. then put it back together. and try it again. when i accelerated there was hesitation, then what seemed like a shot of fuel and a momentary 6 cylinder smoothness, then back to missing.

if anyone has been through this and has some thoughts about diagnosing please post. i am going back to work on the truck and will check in here after the swing shift.



thanks Y'all, and happy wrench bending

 

https://www.youtube.com/watch?v=4_EFGAFxi1w

Sounds like a bad wire or plug. The video is good at showing a way to check for errant sparks with a misting test.