Tag: troubleshooting

11.6 Oxygen Sensor Issues

11.6.1 Fuel Table Cells Show Grey But The Motorcycle Doesn’t Run Well

First, check for any intake leaks or possible faulty sensors. Tuning should ONLY be done on mechanically healthy motorcycles.
Sensor data is largely dependent on the sensor environment. For example, in some earlier model stock exhausts, the rear sensor is positioned poorly. This ends up causing the cylinder to be leaned out when “tuned”. The standard Harley motorcycle oxygen sensors are also limited by design. The sensor is designed to monitor AFR (lambda) to allow small real time adjustments in high MPG conditions, outside of those conditions, the sensor is unreliable and inaccurate. This is why Direct Links AFR mode using the motorcycles sensors creates a temporary lean condition and target while calibrating steps are taken.

11.5 Backup and Restore

11.5.1 Why Should I Make a Backup?

Direct Link creates a robust image of the ECUs programming. While it is exceedingly rare that such a thing is actually needed or used, it is very handy to diagnose and isolate possible emerging mechanical issues or just to evaluate the before and after. For a few minutes of patience, you ensure the reversibility of any programming going forward.

11.4 Idle Issues

11.4.3 Irratic Idle on Startup

It is likely that IAC values are not ideal for your motorcycle and what you may be experiencing is the ECU trying to compensate for these adverse values. If this behavior occurs independent of engine temperature, adjust the Starting point on the IAC table +/- 20% (found under Edit-Table). If it seems to only be at colder or warmer temperatures, adjust the IAC steps in the problematic temperature range +/- 20%. It is more common to reduce the IAC values than it is to increase them, try both, program these changes to the ECU and see if the idle condition has improved. Also, if your tachometer jumps to a very high number review tips 11.4.4 & 11.4.5 regarding spark and spark at idle.