Prelude L4-1958cc DOHC (1989)
Throttle Body: Description and Operation
Throttle Body
The Throttle Body, mounted on the intake manifold, is of the single-barrel, side-draft style. The throttle valve is heated by coolant from the cylinder
head. The idle adjusting screw, located on top, is used to vary the amount of air bypassing the throttle valve to adjust idle speed up/down. The
canister/purge port is also located on top and is used to purge the EVAP system. For a more thorough discussion of the canister/purge port, see "
EMISSION CONTROLS".