I could be wrong but I don't think the ignition start/run module has any connection to high drive speed. The tach signal to the module is how the module knows the engine is running, if you don't have a tach signal it will cause the engine to start/run for a few seconds and then it will die. You mentioned you "calibrated" the controller, does that mean your machine uses the ALC500 circuit board inside the platform box? If yes, I'd try swapping the drive controller with the boom/swing controller if they're both dual axis. Of course you'll have to calibrate both controllers again, but see if that makes the drive work proper.