I have to add that putting cng with efi car becomes really frustrating sometimes as the car doesnt accelerate when you want it to. And i have a theory on it:
I think the reason is simple. CNG, EFI system and Automatic transmission all have their own ICs. And i dont think that they coordinate very well.
When you push the throttle first the CNG system will decide weather it wants to give the gas, then the EFi system will decide on the mixture and then the A/t will decide weather it wants to shift down for better acceleration. And sometimes one of them decides that accelerating is not a good idea, which really pisses me off.
What do you guys think?