Brief Description: Mapped the ECU AFRs According to Instructions
Mapped the ECU AFRs According to Instructions for the SDS ECU. This called for running the engine up in 100 RPM intervals and noting the AFR readings on the handheld ECU Programmer. If the AFR reading was in error for a RPM, doing some math gave the new computer setting to be input into the ECU. The goal was to keep the AFR between 10.5 and 12. The 10.5 AFR is needed for all high power settings to provide a rich mixture for adequate engine cooling and dedonation protection. The 12 AFR is adequate for low RPM, low power settings such as ground maneuvering. The 11 and 11.5 AFRs are used for the high and lower cruise power settings. The mapping needs to be done repeatedly untill the AFRs are consistently correct. Doing the math and adjusting the ECU settings is needed several times before the mapping is completed. The mixture adjustment knob needs to be in the Zero position during the mapping. This turned out to be a problem. When I installed the knob, I clocked the center of the knob throw at the twelve o'clock position. The first attempt to map the engine AFRs were made in this position. Later, I noticed that the handheld ECU Programmer showed the zero position of the knob not to be at this 12 o'clock position. The useful range of the knob is quite narrow and not at the center of the rotational range. After positioning the actual zero position of the knob at the 12 o'clock position using the Programmer, the entire engine ECU AFR mapping needed to be repeated.
