Ok, here is my idea... Input appreciated!

[Bluevitz-rs]

Originally Posted by sito

Hi guys,

I just swapped the 1zzfe throttle body without the changing the chip and adjusting the idle screw...

No CEL for my car yet.. and the response is great....

But when i start my car this morning, the rpm shoots up to 2500 and after 2 mins, returns to 800... And when i turn on the aircon, the rpm shoots up to 1800 when the fan kicks in, and drops to 1000 when the fan stopped. These symptoms happen when my car is in stationary mode (or gear engages in P mode). Other than that, when i was driving in the city or highway, no other abnormalities found.

I was wondering is there anyone who do the mod faces the same problem as me? I'm not sure whether my pivot 3 drive (throttle controller) causes this? Cos my current pivot 3 drive is using harness for 1nzfe, but after the tb swap, i'm not too sure do i need to change the harness.

Hope you guys can help.
Thanks!!!

It's simply because the throttle body is designed to work with a bigger motor. When the ECU tells it to open to start the car, or that the A/C has turned on, it moves the throttle the same amount as the 1NZ tb, but because the opening is bigger, it lets more air in causing the higher idle.