MicroSquirt.com read only forum (Jan.15,2018)

The first might be a "work as designed" but I will ask anyways:

I noticed when I switch the ignition to ON while having the laptop connected via SERIAL cable with Megatune running the laptop beeps once and the fuel pump runs for about 3 seconds and then shuts off. Megatune connects to MS-II and starts displaying signals. I can start the car normally and the fuel pump runs once I crank.

If I have the laptop not connected and switch the ignition to ON the fuel pump does not do this initial 3-second run. WHY?? I can still start the car and the fuel pump starts when I crank. Furthermore, once the ignition is ON and I hook up the serial port after that I won't be able to communicate to the MS-II. I always have to cycle power by turning the ignition to OFF and back to ON. Normal??

And yes, I also have issues making changes to the ignition table stick. It seems more often than not MS-II defaults back to the original values for RPM and MAP bins after cycling power.

Ingo

Something does not seem right there.

When you turn key to on/run, the fuel pump is priming the line, and on ECUs as a precaution, the pump will not run when no rpm is detected after a few seconds. But it should do this all the time regardless if a laptop is hooked up or not.

Next, you should be able to connect the laptop before or after the ignition is on and it should communicate with the Megasquirt. Recycling power should not be necessary.

As for ignition table, are you sure you are using 'burn to ecu' after changes are made. When you change the table in real time you are updating the Ram and not the Flash (I think thats the order). So when the power recycles, changes are lost when power is cut to the ram.

Other may have some advice, on solution. It would help if you gave some info on megsquirt versions and software used.