LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 1981 >> Pickup J20, AWD >> Repair and Diagnosis >> Engine Performance >> Ignition System >> Spark Control Systems >> Testing >> Reverse Delay Valve
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Reverse Delay Valve

  1. Connect external vacuum source to port on colored (non-white) side of delay valve. Connect one end of a 24" rubber hose to vacuum gauge and the other end to port on white side of valve.
  2. With elapsed time device in view and a constant 10 in. Hg of vacuum applied, note time required for gauge pointer to move from 0 in. Hg to 8 in. Hg.
  3. If valve fails to meet time limits, replace valve. If valve meets specifications, install with non-white side toward vacuum source.
Reverse Delay Valve Time Limits(1)

Valve Color Min. Time Max. Time
White/Purple 0.3 0.7
White/Gray 0.6 1.6
White/Gold 0.8 2.3
White/Brown 1.0 3.0
White/Yellow 4.5 13.2
White/Red 14.0 47.2
(1) Time in seconds.