sm4, multiplexer and 2 r500 cdi 8 coils

[stangracing]

ii have the above on a ford v8, if i turn the ignition on and dont start the engine when i turn off ignition it fires the coils and ignites any fuel in the cylinders, any ideas ?

[Mellberg]

Its the multiplexer that do this. We solve the problem with to connect the ignition input to the CDI´s to the same source that go to fuelpump and injectors (brown lead).
Then the CDI is without power when you have the ignition turned on and the engine dont run. This also make the CDI´s does not warm up when you have the ignition on.

[stangracing]

thanks for that will try that in the morning, it backfired up the inlet will have to check for bent pushrods

[Hocky]

Have you confirmed that this works as a solution?

This was the biggest thrill at the dyno the last time ;)

Its the multiplexer that do this. We solve the problem with to connect the ignition input to the CDI´s to the same source that go to fuelpump and injectors (brown lead).
Then the CDI is without power when you have the ignition turned on and the engine dont run. This also make the CDI´s does not warm up when you have the ignition on.

[Mellberg]

Yes this work fine on the 5 and 6 cylinder engine with the same problem that we have in the dyno with yours.

[stangracing]

yes this works fine
steve