Porsche 928 Workshop Manual page 426

25
Fuel System
928
1. Adjust control screw on throttle housing until
specified speed is reached.
8. Adjust mixture. Insert Special Tool 9134
through funnel-shaped opening into spring-
loaded driver in mixture control unit. Press
down special tool approx. 18 mm to engage
spring-loaded drive in mixture control screw.
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Important
It is essential to conform with the following points.
a) Always make CO level adjustments from lea"
to rich. Example: when mixture is toa rich.
first turn mixture control screw counterclock-
wise further than necessary and then clockwise
to adjust to specifications.
b) lust turn control slightly, since the smallest
adjustment will change CO level considerably.
9. Turn clockwise for richer
or
counterclockwise for leaner mixture.
10. Remove special tool.
11. Accelerate engine briefly.
12. Wait until CO tester shows exhaust gas con-
centration at idle speed.
See page 25 - 6 for adjusting data.
If necessary. repeat adjusting procedures.
l
13. Recheck idle speed and correct, if necessary.
14. Remove plug after completion of adjustments.
Attach air hose to diverter valve.
25 - 4
Adjusting Idle and CO
I, 1978 -
Printed in Germany