Porsche 928 Workshop Manual page 445

25
Fuel Mixture 928
CHECKING FUNCTION OF HOT START VALVE (CIS)
(to Reduce Control Pressure for Warm Start)
Test Requirement:
Engine warm, coolant temperature about + 60 "Cl
140 "F or warmer.
1. Connect pressure tester and switch to position 2.
2. Operate starter. This opens the hot start valve and
drops the control pressure.
Specification: 0.5 - 0.8 bar (note brief delayed
action time).
3. If applicable, replace hot start valve or check
temperature switch, i.e. temperature switch must
have switched to through flow Iground).
CHECKING HOT START VALVE FOR
LEAKS (CIS)
1. Detach and plug fuel return line. 2. Bridge fuel pump relay.
3. Hot start valve must be absolutely tight, i. e. fuel
must not escape on fuel return connection.
a
25.12b Checking Function of Hot Start Valve (CIS)
Checking Hot Start Valve for Leaks (CIS)
VI, 1982 -
Printed
in Germany