I converted my 85 to speed density from a MAF system. So far I feel I have made good progress. The car started, but is running badly. I have two codes set, code 41 Cylinder select and code 43 ESC errors. I am using a memcal from a 3.1l V6. I jumped pin 13 to pin 10 on the 16 pin chip. This is the HAC from Thirdgen to convert the chip to 8 cylindars. I assume there is something to do with that memcal as to why I am getting the cylinder select error. The 85 ECM 1226870 has a grounded input for selecting the ECM mode. Does the 1227730 ECM have a input like that, or is the HAC identified on Third Gen correct. I am a little worried about the ESC Code 43. I was under the impression the ECM/MEMCAL controlled the spark advance by direct input from the knock sensor. The 85 system had a separate ESC module that the knock sensor plugs into. The ESC module would signal the ECM to retard timing or not. By the wiring diagram for the 1227730 ECM, the ESC module is eliminated. So I have the knock sensor connecting directly to the EMC. Is this correct? I started my project (engine rebuild from a 305 to a 383) with an engine from the junk yard. It was a 1990 TBI 5.7L truck engine. That engine had a separate ESC module like my 85. This is why I wonder if I wired the knock sensor correctly or not.