CYLINDER PACK AS 20R0631 - Caterpillar

The throttle linkages contain mechanical stops to prevent breakage of the rotating wheel on the front of the throttle position sensor. The low idle stop in the throttle linkages should be adjusted to allow little or no downward motion of the foot pedal before the engine rpm increases ("dead pedal" motion), and proper adjustment is necessary for the brake retarder enable to function properly. Excessive "dead pedal" motion is undesirable.With the 3176 engine, the maximum rpm obtainable is the selected rpm rating +20 rpm (300 bhp @ 1800 rpm rating would have a high idle rpm of 1820 even if the Top Engine Limit (TEL) is programmed to a lower value such as 1750 rpm).With the 3176 engine, the high idle rpm in neutral is obtained before the throttle position sensor reaches its maximum signal. If the throttle linkage stop is set "by ear", the engine will not obtain full engine horsepower.A (7X1055) 3176 Digital Diagnostic Tool (DDT) or (8T8697) Electronic Control Analyzer Programmer (ECAP) must be used to adjust the full throttle linkage position mechanical stop (see Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913, or the Testing And Adjusting section of Systems Operation, Testing And Adjusting, Form No. SENR3909, for more information). Excessive motion past the full throttle position can damage the rotating disc on the front of the throttle position sensor.