Check the K line from the device at the OBD plug. This ensures that the cable is correct (if it's a home made job), and it's easy access the pins. Just connect to the ground (PIN 5) and the K line (PIN 7). You'll see the device maintain a high of 12 volts (or 5 or so if running from USB connector), then fall down to zero three time (or so) as it tries to connect. The auto MUST see this to react.
For the timing variances see
prj.perquin.com where it lists the 14230 timings. The 9141 should be the same, but I can't verify.
It states:
0-20 Inter byte timing in ECU response
25-50 Time between end of tester request and start of ECU response or between ECU responses
25-5000 Extended mode for "rspPending"
55-5000 Time between end of ECU response and start of new tester request, or time between end of tester
request and start of new request if ECU doesn't respond */
5-20 Inter byte time in tester request
We currently wait 3000 ms between attempts (maybe your car needs a longer wait period?)
We currently wait 60ms before listening for ECU response, maybe your car responds at earlier and we miss part of it's response?
Can you test your gauge on another car?
Yes, the K line on the car side is held high, and falls to zero for communication.