On a 1990 Wrangler with a 4.2 liter, what is supposed to be disconnected before the timing is set? I know about the vacuum advance on the distributor, are the 3 vacuum valves on the rear of the valve cover also supposed to be disconnected? What should it be set at for 9,000 feet?
4.2L 6-Cylinder
1. Set parking brake. Shift automatic transmission to Park or manual transmission to Neutral. With A/C off, start engine and attain normal operating temperature.
2. With ignition OFF, connect an ignition timing light and a calibrated, expanded-scale tachometer.
3. Disconnect 4 " and 10 " Hg (CEC System) vacuum switch assembly wire connector (located at top of valve cover). Disconnect and plug distributor vacuum advance hose.
4. Start engine, increase engine speed to 1600 RPM and check ignition timing. Adjust timing to specification listed on Emission Control Information label (if necessary). Tighten distributor hold-down clamp and recheck ignition timing.
5. Turn engine off and remove timing light and tachometer. Connect No. 1 spark plug lead, if disconnected. Unplug and connect distributor vacuum advance hose. Connect vacuum switch assembly wire connector.
NOTE: If timing light has an adjustable advance control feature, turn control to OFF position.
Timing is set per the emissions tag under hood.
1,993 views
Usually answered in minutes!
×