1999 Honda City 1.5 EX (Asian market vehicle) doesn't kick down when pressing throttle at low speeds

I’ve tagged this as a Civic but it’s a 1999 Honda City 1.5 EX.

Normally this car would shift to 2nd at 20km/hr and 3rd at 40. But if I hit 40+ and it shifts into third, then coast for a while and let the speed drop to below 40 (say 35), when I push the throttle now the car doesn’t kick down and it feels like it has almost no power even if I push the throttle to the floor. The feeling of no power lasts for about 2 or 3 seconds, and then the car downshifts automatically and the RPMs shoot up. Quite dangerous trying to move around quickly in Asian city traffic. I adjusted the kickdown cable to make it stiffer, but now the same problem happens at a higher speed and shifting at a higher RPM.

Any ideas? Thanks…

Maybe the throttle plate is sticking to built-up carbon. I cleaned out a lot of carbon on my 1999 Civic recently when it sometimes hesitated upon pushing the gas pedal. Mine is a manual trans. The problem seems to be fixed.