If your AF-3000-4000-5000 series EFIS with internal engine monitor is suddenly not displying fuel flow, one thing to try while troubleshooting is to relocate the power wire from pin 15 to pin 29. While there are many ways for a fuel flow reading to go awry, one possibility for the loss of signal is that the flow transducer is no longer happy with the 5V power available on pin 15. Pin 29 provides 8V instead, which can sometimes make the difference.