befarrer

iTrader: (1)

I have been chasing a misfire issue with my rotary since I installed it last year. Hot and cold starts are no problem, low rpm is fine under 2500rpm, cruising at 60mph in 5th is fine. I get a misfire start when I am cruising, and start going up a hill (more load), it gets pretty bad maybe 8-10 misfires a second. More throttle or downshifting and it goes away. I also get some bad misfires at WOT above 4000rpm. My engine is a hybrid, its mostly a S4 TII motor with S5 housings and 3mm apex seals, running S4 t2 rotors I think. I have no turbo on it right now, no emissions, running premix. Stock plugs, stock FC ignition, Adaptronic Ecm. I had a S4 na engine prior in the vehicle and had no issues. However, I have since replaced the cas, both coils, plugs, plug wires with no change. I have also leaned and richened the fueling at wot with no change at all. Just yesterday, I tried retarding timing at wot by 15 degrees, made no difference, so I am pretty sure my tune is not causing it. Could my plugs be the issue? They were changed and made no difference, could the heat range or gap be out since its a low compression turbo running na?

j9fd3s

iTrader: (3)

what kind of dwell setting is in the ECU? are you getting 12v at the coils?

i should say, you've gone over the basic stuff. i have found that the FC is picky about wires, they should be under 16k ohms, and new is like 7k. i have seen some brands of new wires that are like 16k, and these will not work. the more resistance in the spark plug/wire the less power is available to fire the plug, but potentially RFI goes up.

befarrer

iTrader: (1)

I believe I have found my issue. I converted to GM truck coils so I can have full sequential spark, and while checking my timing, I noticed it wasn't the most stable with the timing locked, it jumped around a couple degrees. I changed the CAS again with one I have not used before, and timing was stable, and I dont have any misfires at WOT anymore. Guess I have 2 bad CAS, that act the same way. I have not driven on an extended trip, or at highway speed, I need to make a bracket for my coils, as the original GM bracket is zip tied to the fender well, and the stock plug wires are held onto the coils with electrical tape, but even with all this hillbilly rigging, its a huge improvement, now off to get plug wires that work, and material to make a mount for the coils.