I am so close but still no spark on the leading coil.

Either the leading coil is bad and my spare is bad as well or MegaSquirt 2 3.57 PCB isn't putting out enough voltage on the trigger to get the leading coil to fire.

I think I need 3 to 5 volts but the ECU is only putting out 2.46 volts. ( open circuit trigger not connected to coil voltage 3 volts.) I have used a scope and have a 4 mil second pulse width.

Is there a way to boost the voltage so I can get the lead coil to fire? Amplifier circuit? Jumper to higher source?

Please see my short video and I am totally open to any suggestions. This FC engine is to go into my restoration project of an FB body. The coil firing problem is holding me up.

Thanks.

Ark1

 

Do you have a hefty ground supplied to the frame of the coil pack? It is a little hard to tell in the video.

 

The ground wire goes all the way back to the Megasquirt controller and also has a tail to the frame of the test stand.

DIY Auto tune confirmed in an email to me today that I should have 5 volts. Although I am not sure why I only have 2.4 volts the problem now is identified and it is a matter of trouble shooting the board at their direction.

Just a bit of a run down. The board came with a broken R20 resistor. This gated Q5 and I burnt out the secondary injectors while i was loading the program on my engine ECU. To complicate issues Q6 transistor would not fully open the circuit that sends the trigger pulse to the leading coil so it too was changed. So now that I know what I am looking for I suspect that the ignitor on the leading coil must disregard the low signal being sent as noise and therefore no spark on the leading spark plugs.

Thanks for your reply. I have been at this for 6 weeks. I need to run this engine before I install it in the car.

Ark1.