Carbureted

Disconnect and plug parking brake vacuum hose at vacuum release cylinder.

Engines Without Fuel Injection:
4.1L (252) eng: Adjust idle speed with cooling fan not running. Disconnect and plug vacuum hose at EGR valve and canister purge hose as well as purge control valve if so equipped.

All engines: Check idle and if not at specified slow idle rpm, adjust idle speed screw or solenoid adjustment nut to obtain specified rpm.

Air-conditioned models equipped with idle speed-up solenoid, turn AC on, disconnect compressor clutch wire and with solenoid fully extended, adjust solenoid to obtain specified rpm. Turn air conditioner off and reconnect compressor lead.

Set fast idle to specified rpm.

Engines With Fuel Injection:
Adjust idle bypass screw to specified slow idle.

Diesel eng
Adjust screw on injection pump to set idle speed. To set fast idle, install a jumper wire between the terminals of the cold advance switch. Disconnect EGR and adjust fast idle solenoid to specification.