so i got the scope the other day and have tryed to work with it to help see whats going on

mostly i am looking for a waveform that does not mach the others

fuel injector amps and volts and timing looks good . tryed to add pic
coils + and - wires timing show the same on amps volts as no coil stands out
but when i try to add the prob onto the spark plug wire its self to see if all of the coils are firing in the same way and there all nuts its seems
i have tryed to look at whats a spark waveform should look like for a GM 2004 coil and its very hard to under stand what i should be looking for with a spark if no fuel or to much fuel and so on and so on
in the end i feel this is where i well find my misfire that is so bad but in every test i have done i dont see any thing wrong but again adding that i am not 100% sure what i am looking for and used reference waveforms in the software that came with the scope

i really really need help with this

ok it did add the pics .. pic on left is spark lower line is what i have . what is not all ways the same is each time that a coil fires is after the burn time it jumps up like that and some times all over the place
each coil is all firing the same and just like in the pic and they are all over the place . not sure if i dont have a setting set right or have 8 bad or good coils?

pic on right is fuel injector is volts and current

both lines on top in each pic is reference line only

If it'* running lean you'd have a random misfire that you'd never be able to narrow down by disconnecting a cylinder at a time. At the same time, the scope would likely look the same on all cylinders.

it is very sad but i think i may have to just give in . i may have to start thinking about maybe getting a new RV and starting over

but today for the fun of it i got a new set of spark plug wires to see if that would help . it did not . the misfire is still there and timed with the timing of the motor
yes unplugging each coil/injectors 1 at a time does not show where the miss is
the scope seems to show the PCM is sending and receiving and doing what it should be doing

the only old parts left is coils fuel injectors O2s PCM
the only thing left that sands out is the fuel psi pulses with the misfire by 3 psi like a heart beat i cant tell if it drops or is going up
scope shows volts and current looks good on them and i can see the pin inside the injectors drop but i cant see them move up in the current line

i gave in and order a set of coils and injectors

Seriously, you've gone to enormous expense to diagnose this thing, including a scope and a complete rebuild and countless parts and everything. Why not get the PCM reprogrammed back to stock?

. . . and coils and injectors . . . . . . .

Then get the PCM defaulted maybe?

I was hoping to see if the scope would have shown a bad driver in the PCM for a coil or a injector but all outputs seems to show the right timing and no drop outs
Coils and injectors are getting there commands to fire but the spark waveform looks nuts to me when playing with RMP as its all over the place on all 8
I am still very open to trying a new PCM but from every thing i see the PCM is working as it should but i well try a new PCM if new parts dont work . NO really i well try if this does not work
LTFT on both sides are -4 drive side and -3 passenger so even with fuel trim low some there still spot on
Even knowing the scope is saying the injectors are working the bump in fuel PSI timed with the miss has me guessing fuel is not
Moving or moving to fast in a injector but the - fuel trim makes me think fuel at O2 sensors from misfire

O 1 thing i forgot to add was driving side 4 coils shows a what looks like 2volt drop when firing on ground wire . i well run a new heaver Gage wire from my splice when i install new coils
its 2volt or 2Mvolt not sure . getting to know the scope setting are fun

i have not looked at the out puts of the cam or crank sensors tho and feel i should as the RPM jumps around every now and then
the misfire was every now and thin before the motor rebuild but is now really timed to RPM so i think some thing happen when reinstall
timing is av 25% at idle but was in the 30s before reman so the pcm pulled the timing back at idle

I'm not talking about a new PCM. I think the current one is fine. I'm talking getting the current one reprogrammed so it doesn't have the aftermarket config on it.

humm .the doner vin i used still had a anti theft system and wrong gear ratio

it did have the right 02 sensor setup and del EGR removed on that year and was street legal setup

in the end i would still have to have some kind of editing so the config for the anti theft system and wrong gear ratio and for it to talk to the allison 1000 trans