so with that 93 Rx7 Twin turbo with the blown motor, I was able to get a shop to do a JDM motor swap for me. It drives awsome, lots of power and fast. The only thing is odd is that when I first start it (can be cool or hot) the car idles 2200rpm then drops to 1000rpm then back up to 2200rpm then drops again in a fast pase. Does anyone know anything about this? Also noticed when at idle speed the Oil pressure gauge reads 0 and when driving the needle is in the middle. Its been 4 days of solid driving and I still smell nasty coolant. The old engine was burning coolant but I think after 4 days, the smell should be gone by now?.

 

Check your TPS.

Sounds like its all whacked out.

 

Sounds like a possible coolant leak around the throttle body which would effect the thermo wax rod. The thermo wax rod is a known cause of the "surging" idle that you described. The coolant line is on the back of the throttle body. You can hold open that wax rod arm though to see if the idle corrects itself.