Bill Gates has corrupted my Megasquirt1

[dggt6]

Hi Guys,
Has anyone come across a situation where you have to "turn the megasquirt off, then on again" before the car will start?????
Yes. Very weird!!
The MS1 is working well when working but I have had this persistent problem for over a year.

Turn the ignition on,the fuel pumps runs, crank the engine but it will not fire-up. Turn ignition off. Turn ignition on,the fuel pumps runs, crank engine but it will not fire-up. The Tacho does not move from 0 rpm

Turn the ignition on, the fuel pumps runs, now, disconnect the power to the MS and reconnect, crank the engine, the fuel pumps runs, and the engine fires up immediately.

If the engine now stalls or you switch it off, it will not start again until you turn the MS off then on again. It would appear that something is not "re-setting" itself.
I have replaced the relays numerous times with no effect.
I have replaced my ignition switch with 2 other second hand switches with no effect.

Has anyone any idea what scenario would cause this strange situation?

Thanks,
Doug

[jsmcortina]

What are you using for tach input?

I was wondering if you had a hall sensor or EDIS module that was receiving power from the fuel-pump relay. In that case you would only get a tach signal if you crank while the fuel-pump is running.

James

[dggt6]

Hello James,
I am using an EDIS module in a 1968 Triumph GT6.

I can't remember off hand where I have powered the EDIS from, but I think I setup a fuse panel powered by the main relay (as per typical MS generic diagram) and powered the EDIS from that. The EDIS should not be connected to the fuel pump circuit.

The fuel pump doesnt have to be running for my car to start. I have set up a switch on the dash to disconnect and connect the MS. My routine to start the car is... switch on the ignition, turn the MS on and off (the fuel pump runs for the 2 seconds) then I wait 20 seconds for Tunerstudio to reconnect, then turn the key and the car starts.!
I am really surprised that just turning the ignition key back to the off position doesn't do the "re-set". There has to be an actual physical power disconnection.

Do I get the prize for the weirdest problem??????

Thanks,
Doug

[elaw]

Without the switch in the circuit, it might be worth using a meter to see if any voltage is supplied to the MS when the ignition is off. Or for that matter, just see if TunerStudio will connect. Perhaps something is backfeeding power to it?