Test Point 10 - Throttle Switch

TEST POINT 10

Throttle Switch

1. Connect ohmmeter between term. 2 on DME plug and ground.
Specifications with throttle closed: zero ohm
Specifications with throttle open: infinite ohms
Switching over must take place even when throttle is only slightly open (approx. 1°).
2. Connect ohmmeter between term. 3 of DME plug and ground.
Specification with throttle closed: infinite ohms.
Specification with throttle wide open: zero ohm.
Switching must take place immediately before full throttle.
If switching points are not correct, repeat test direct on throttle switch by connecting ohmmeter term. 18 (ground; center flat plug on throttle switch) and term. 2 or term. 3.

Adjusting Throttle Switch

1. Remove throttle housing.
2. Unscrew throttle switch mounting screws.




3. Hold throttle in closed position. Turn switch until inner stop is felt. Throttle must not be moved.
4. Tighten switch mounting screws. Throttle must rest firmly on stop screw.

Checking Coasting Shut-off (Stopping of Injection Signal)

1. Pull off plug on throttle switch.
2. Connect term. 2 (idle contact) and term. 18 on disconnected plug with an auxiliary lead. This will simulate a closed throttle for the DME control unit. (Only use suitable flat plugs on auxiliary lead.)
3. Start engine and increase speed to about 1600 rpm. Engine should begin to surge, i.e. the injection signal will be stopped above 1600 rpm.

Check Full Throttle Enrichment

1. Start engine and run at idle speed.
2. Connect term. 3 (full throttle contact) and term. 18 on disconnected plug. Engine speed should drop.