After the engine has warmed up, this vacuum operated system forces the fast idle cam to move to the third step, which, in turn, lowers the engine speed.
See Figures 1, 2 and 3
- Disconnect the vacuum hose from the fast idle cam breaker diaphragm.
- While holding the throttle valve slightly open, pull up the fast idle cam linkage, then release the throttle. This will set the fast idle cam.
- Start the engine but do not touch the gas pedal.
- Reconnect the hose. The fast idle cam should be released to the third step and the engine speed should thereby be lowered.
- Apply vacuum to the FICB diaphragm and check that the linkage moves. If it does not, replace the diaphragm.
- Check the VSV and the TVSV, as detailed under Evaporative Emission Control in Driveability & Emission Controls .