Ok so I just put together an ls vtec in my ej8. Everything works properly except for an Issue I had with the tach going crazy sometimes. I researched and determined it may be a possible icm issue. So I changed the icm thus problem seemed to have went away but had not. So I mess with the dizzy plug while the engine was running and the car shut down. I believe I traced it out to the black wire with yellow stripe believe it's some sort of rpm signal wire? Btw this is an obd2a setup. I pulled the pin out of connector checked it and reinstalled only to still have no fix. Does anyone have any idea why moving the wire would cause such an issue?

 

the black wire with yellow is not the rpm signal wire

 

There are pics of the ecu pin-out on here. I usually just look through google though. When playing with the dizzy wiring, it's very easy to interupt the signals and subsequently throw the spark off. See if you can't round up another dizzy and see if it's in the dizzy or not.

 

Black/yellow is power to the coil and the igniter.

 

Ok. Thanks for the help guys. I was trying to avoid the new dizzy but seems like that is the right way to fix the issue

 

IF it is not in the harness itself. Try a spare one first. i hate spending money on parts just to find out it's something other than the part I just replaced.

 

Your looking for the Yellow/Green wire