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

I want to run injection for both petrol and LPG on a V8, will MS be able to drive two seperate sets of 8 injectors or will i need to build some sort of relay switching board controlled by the LPG switch to change which injector set MS is controlling?

It could drive two separate banks of 8 injectors; that is about its limit but it can be done. Each one can be given its own fuel map by running in dual table mode.

I am investigating doing this on a v12 and have made a mod on the v3 board to the input of U4 so that both injector driver circuits are used. I've hooked up a small DPDT relay to send PWM0-1 to both pins 2&4 of U4 for petrol and PWM1-1 to both pins 2&4 of U4 for LPG. You could equally do this with a logic circuit.

The second daughterboard plugs into (and intercepts) the signals between the output of the processor and input to U4. This means both driver circuits either see Table 1 or Table 3, depending on the table switching.

A separate changeover relay will then supply 12v to either the petrol or the lpg injectors depending on the table switch. MS simply sinks whichever ones are connected to 12v

kind regards
Marek

im ditching this idea now that im using the car daily (and its now my only running car), i was thinking something a lot more simple by using throttle body injection of LPG and leaving the petrol system alone. Essentially i want to get rid of the LPG mixer which imposes a restricion on the air inlet inorder for the venturi to work, Plus it makes my air box sit a few cm higher an interfere with the hood insulating pad. Very annoying as they are quite expensive