Red 86 rx-7

Is it possible for carbon build up to cause a rotary to Idle like crap.I mean if one of the bath tubbs on one side of a rotor was gunked with carbon would that throw off the natural balance of the engine.I hve done everything under the sun to get my car to Idle.The engine just sits there and jumps around on it's mounts?I even did my ECU grounds and it still stummbles at 3800 .I cleaned the 5th and 6th ports replaced injectors,plugs wires,alt,batt,all new engine grounds..Is there anything I am missing this car will not start hot! I have even checked intake temp sensor,FPR selenoid,Cleaned BAC,all new gaskets.I'm ready to tear the motor out and throw another one in!

White_FC

Carbon build up will not have an effect on idle stability or balance of the rotors... At all
This is not your problem.

Have you done a compression check on your engine? You might have **** a seal.
Even just a simple one?(ie, take plugs out and turn engine over, listen to even pulses.)

Red 86 rx-7

yes I have done a comp test both listening for even pulses and tested with a piston comp gauge I got readings of 30,30,30 on both rotors.I'm gonna test the engine again in the morning.The engine has 157,000 miles on it.I'm starting to lean more towards replacing the engine with my spare engine I took out of my 87...that engine is a rebuild with 30,000 miles on it strong comp and less oil leaks.....