Hello, i have a RX7 FC turbo2 from 1988. The problem i have is that it runs very rich at light throttle but runs perfect while slowly accelerating, at light throttle/ just touching the gas pedal afr`s will be between 11 and 12. If i step on the gas a little more it will run perfect afr`s between 14 at 50kmph and 14.2 on the highway.

I installed a new o2 sensor that helped the afr`s on the highway.

Things i have done to the car:
Different exhaust
No more catalysator
Air pump delete
ACV delete
Rebuild s5 turbo
Aem wideband

Anyone know what could cause this

Thanks for any help

 

That's pretty par for the course. If you're running stock computer, they run rather rich from the factory, and the fact that you removed the air pump is contributing to the "rich" condition.

 

Thanks for the anwser, i suspected it but i hoped it would not matter so much. Guess i will start saving for a good standalone

 

These engines were tuned to the leanest mixture possible without misfires, but due to the porting (internal EGR) this is only in the 12's. which is why they then add the air pump.

the revisions for the Rx8 were primarily to fix this so the engine can just be run at 14:7 with no air pump like every other car