I have a supercharged 13B 4 port (street ported) with a Holley carb in a 1983 RX7. The car was running wonderfully until a few weeks ago. Now the car starts up fine but with an extremely rough idle, a big lope. The 13B doesn't have any trouble maintaining idle. It's like a V8 with a really big cam in it. I pulled the plugs to discover that the leading plugs were nearly fouled but the trailing plugs looked pretty good. Regardless, I dropped in a fresh set of NGKs and it made very little difference. I haven't done a compression test yet, but the car has no trouble revving to 8-9,000 RPMs. To drive the car now, the motor, under load, is sluggish, and you can feel it surge slightly like it is trying to go ahead and haul tail. All of my ignition basics are fresh (new cap, rotor, wires, and 2 Crane Hi-Energy coils). We even changed the carb to a different Holley carb, and no difference. If it is internal, my guess is that it may be a corner seal, but everything seems to be pointing towards some type of ignition failure. Any of you in here that can shed some light on this, I would greatly appreciate it. Thanks for your time.



Todd.