I have made a series of measurements including TBI memcals and posted the results. TBI memcals show 7.5k between the two pins.
http://www.gearhead-efi.com/Fuel-Inj...ull=1#post3374
The images above are for specific chips in the memcal. Those chips are connected to numbered pins on the memcal. Understanding how the ecm uses voltage on pin 56 to determine fueling mode involves studying the ecm schematics and / or having access to GM documentation. It may be a distraction if the goal is simply to make your engine run well.
Here is some work done by Cliff Harris which shows the memcal pinouts which correspond to the specific chip in the pictures above. Cliff's work has been very beneficial to this hobby. Notice how pins 53, 56, and 56 work together to provide the desired voltage for fueling mode select.
http://www.misterpeachy.com/VettePics/MEMCAL-ECM.pdf
Bookmarks