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Cold Lock-Out Spark System

  1. Remove air cleaner. Remove air cleaner Vacuum Delay Valve (VDV). Test air cleaner VDV before continuing with test. See FORD MOTOR CO. VACUUM DELAY VALVE article in this section. If VDV checks defective, replace with new VDV at end of testing.
  2. Install a temporary connector in vacuum hose where VDV was removed. Install a test vacuum "T" and vacuum gauge in vacuum hose at distributor. With engine coolant below 128°F, accelerate engine quickly to 2500 RPM and release throttle. Vacuum at distributor should bleed off slowly. If not, replace restrictor.
  3. With engine coolant above 128°F, repeat engine acceleration test. Vacuum to distributor should rise and fall with throttle operation with no delay. If vacuum is still delayed, replace PVS. Remove temporary connector and install VDV.
Fig 1: Cold Lock-Out Spark System
G09327222Courtesy of FORD MOTOR CO.