The Latin RX7

Hello everyone, I have an FC with a S4 turbo engine that I rebuilt over two years ago. It has new housings, new irons, and all OEM springs and seals, except for the apex seals which are E&J. The car runs quite well, with good vacuum (17 in/Hg at around 1000 rpm) and starts reliably in both cold and hot temperatures. However, I've encountered a wierd issue where the front leading spark plug consistently fouls after every couple of short drives when I take the car out for a spin on weekends. I've checked the injectors and confirmed they are in good condition. I even swapped their positions, but the problem persists. Additionally, I swapped the coils to troubleshoot, but the issue remains unchanged. Surprisingly, the rear plugs appear to be in good condition with a brownish color. The car is premixed with 1 oz per gallon (without OMP). I'm unsure what else to check. I'm thinking it probably is an internal engine problem. While I haven't had the chance to check the compression due to the unavailability of a tester at the moment, the engine has three even pulses on each rotor while cranking the engine without the leading plugs. The car smokes a little, but probably due to the fact that I premix and/or the lack of a proper drain on my S366SX-E turbo. Any help or guidance would be greatly appreciated.

Howard Coleman

iTrader: (6)

did you check the spark plug wire? i would also run it in the dark and check for spark leakage.

The Latin RX7

Yes I also checked for spark leakage at night but did not find any spark jumping around the wires. I really don't know what else to look for.