9.
Position the remaining injector rack control levers as outlined in Steps 6 and 7.
10. Connect the fuel rod to the injector control tube lever.
11. Turn the idle speed adjusting screw in until it projects 3/16" from the lock nut to permit starting the engine. Tighten
the lock nut.
12. Use a new gasket and replace the valve rocker cover.
Adjust Maximum No-Load Engine Speed
All governors are properly adjusted before leaving the factory. However, if the governor has been reconditioned or
replaced, and to ensure the engine speed will not exceed the recommended no-load speed as given on the engine option
plate, set the maximum no-load speed as follows:
TYPE A GOVERNOR SPRINGS (Fig. 6):
1.
Loosen the lock nut (Fig. 5) and back off the high- speed spring retainer approximately five turns. With the engine
at operating temperature and no- load on the engine, place the speed control lever in the full-fuel position. Turn the high-
speed spring retainer IN until the engine is operating at the recommended no-load speed.
The best method of determining the engine speed is with an accurate tachometer.
3.
Hold the high-speed spring retainer and tighten the lock nut.
TYPE B GOVERNOR SPRINGS (Fig. 6):
1.
Start the engine and after it reaches normal operating temperature, remove the load from the engine.
2.
Place the speed control lever in the maximum speed position and note the engine speed.
3.
Stop the engine and, if necessary, adjust the no-load speed as follows:
a.
Remove the high-speed spring retainer, high- speed spring and plunger.
CAUTION: To prevent the low-speed spring and cap from dropping into the governor, be careful
not to jar the assembly while it is being removed.
b.
Remove the high-speed spring from the high-speed spring plunger and add or remove shims (Fig. 6) as
required to establish the desired engine no-load speed.
NOTE: For each .010" shim added, the engine speed will be increased approximately 10 rpm.
c.
Install the high-speed spring on the plunger and install the spring assembly in the governor housing. Install
the spring retainer in the governor housing and tighten it securely.
d.
Start the engine and recheck the engine no-load speed. Repeat the procedure as necessary to establish the
no-load speed.
Adjust Idle Speed
With the maximum no-load speed properly adjusted, adjust the idle speed as follows:
1.
With the engine running at normal operating temperature and with the buffer screw backed out to avoid contact
with the differential lever, turn the idle speed adjusting screw (Fig. 7) until the engine is operating at approximately 15
rpm below the recommended idle speed.
NOTE: The recommended idle speed for non- EPA certified engines is 500-
600 rpm, but may vary with special engine applications.
2.
Hold the idle speed adjusting screw and tighten the lock nut.
Fig. 7. Adjusting Engine Idle Speed
Page 82
DETROIT DIESEL
Engine Tune Up
