5000S Sedan L5-2226cc 2.22L SOHC (KZ) (1985)
Acceleration Enrichment Module: All Technical Service Bulletins
Pressure Gradient Switch - Checking Procedure
Applies To
5000 TURBO
Group
1985
26
Subject
Key Points
Number
OXS System
Checking procedure for pressure gradient
switch (engine code letters KH)
85-26-02
Part Identifier
N/A
(supercedes Product Circular, Group 26, No. 85-01)
August 5, 1985
Beginning with November 1984 production the 5000 Turbo is equipped with a pressure gradient switch for cold acceleration enrichment.
Pressure gradient switch, operation
When engine coolant temperature is below approx. 65~(149~F), vacuum is supplied to the pressure gradient switch through the thermo-pneumatic valve,
located on the left rear of the cylinder head.
During acceleration, until the specified coolant temperature is reached, the pressure gradient switch will close for approx. 0.4 seconds. This will
temporarily ground the OXS frequency valve and provide a duty cycle of 100% for acceleration enrichment.
Pressure Gradient Switch, Checking
Pressure gradient switch, checking
Test conditions
^
engine coolant temp. below 10~C (50~F)
-
unplug electrical connector from pressure gradient switch
-
connect voltmeter between terminals 1 and 2
-
switch ignition ON
^
specification: approx. battery voltage
-
unplug electrical connector from frequency valve
^
specification: approx. 4 volts (measured on pressure gradient switch connector) If specification NOT OK
-
check for open circuit in wiring according to current flow diagram
If wiring OK
-
unplug vacuum line and electrical connector from pressure gradient switch