Watch the fuel pump pressure while slowly
accelerating the angina from idle to maximum speed.
The pressure should always be greater than zero. If
pressure, check to be sure it is still above zero even
during maximum acceleration (maximum engine
power). You can use STE/ICE test 24 with control
function 02 (minimum).
Rapidly accelerating the engine with the transmission
in neutral doesn't work for this engine because the
fuel supply cant increase as fast as the engine can
accelerate so you wont get good test results.
Proper engine performance is dependent
upon the availability of the correct fuel
volume to the injection pump.
Pay attention to when the engine runs rough. If it
runs rough only while warming up after a cold start it
may be a glowplug problem and you should run the
Glowplug Circuit tests.
Rough running may also be caused by air leaks in the
fuel supply lines. Air in the fuel should purge itself
while idling. If rough running occurs after a period of
high speed or high power running but seems to go
away after idling, then look for air leaks in the fuel
supply lines and fittings. if rough running occurs while
driving but idles ok, check the fuel return check valve
for any malfunctions (refer to para. 3-35).
Try to adjust the engine idle speed by
turning the idle speed screw (refer to para 3-44).
Continue testing if you can adjust the
speed properly. If you cannot, notify
Engine must be at normal operating temperature
when making speed checks. Air fitter must be in
place and all accessories (lights, heater fan, etc...)
must be turned off.
This engine has a min-max governor which controls
engine speed at both idle and full throttle.