Vanagon F4-1915cc 1.9L (1984)
Throttle Full Open Switch: Testing and Inspection
Early Version With Two Throttle Switches
Full Throttle Enrichment Switch, Checking
Checking Full Throttle Switch
Note: Full throttle switch supplies the control unit with information to increase amount of fuel injected at full throttle
CAUTION: Do not connect test light to throttle valve switch connectors if control unit is connected
First Check, Throttle Valve Switch
-
Disconnect throttle valve switch connectors
-
Attach ohmmeter to switch 3
Throttle valve closed; switch turned OFF = infinite ohms
Throttle valve full open; switch turned ON = 0 ohms
Second Check, Wiring And Control Unit
-
Run engine at idle for a short time
-
Stop engine and turn ignition ON
-
Pull off connectors from both throttle valve switches
-
Check voltage between connectors of full throttle enrichment switch
Voltage should be approx. 5 volts
If NO, control unit is defective or break in wiring
Third Check, Full Throttle Enrichment
Test conditions:
Result of first and second check must be OK
Throttle valve switch connectors connected
Temperature at temperature sensor II must be minimum 60°C (140°F) and resistance below 550 ohms
CO tester and tachometer connected
Work Procedure:
-
Run engine for about 2 minutes at idle speed
-
Increase idle speed slowly until tachometer reads about 4000 rpm
CO should be between 0.3 to 1.1%
-
With engine at about 4000 rpm, operate full throttle enrichment switch 3 by hand for about 15 seconds
C0 must increase above 1.5%
If NO, control unit is defective
Full Throttle Enrichment Switch, Adjusting
Adjusting The Full Throttle Switch