I've been interested in burning my own PROMs for the ECM for a while and probably can get the money to buy equipment and software for that but I want to rebuild the engine and repaint it sometime soon (while it's cool out). I read in the PROM burning article that it's best to make or buy an ALDL reader to scan the data, so I studied up on how to make one and made an adapter cable and downloaded the TTS powersystems software for my '92 RS w/MPFI L98(not TPI), from ttspowersystems.com. When I plug the adapter into the laptop and run the program, it says that it can communicate with the adapter but can detect no ECM. The voltage to the "M" pin (serial data) is 4.94, which is where it should be. All connections are good and I know that the adapter is working good. I checked to make sure that it is the right program and it is. It's almost like theres a loose connection somewhere, but I'm absolutely, positively sure that there's not. Another thought is that it's not the right converter chip. I'm using the MAX 232. Any help would be appreciated.