Help Need gasoline injector pulse emulation for a Diesel engine

[Thedrive2112]

Hi all, I'm new to the forum and looking for some help. I do natural gas conversions for Diesel engines and I'm working on a new type of injected natural gas kit I'm hoping to bring to market soon. I have the system installed on my test vehicle (2008 dodge ram 2500 with the 6.7L cummins diesel). I'm using a natural gas ECM that was originally designed for gasoline conversions to meter the natural gas delivery. To make a long story short I need a gasoline injector signal (square wave) that will increase with rpm. It looks like the natural gas ECM monitors the duty cycle of the gas injectors to get its timing signal. Diesel injectors operate different than gas injectors so the signal they produce does not work(at least on this cummins it doesn't) my thought is to install a crankshaft position sensor (Hall effect type) and weld some nuts on the flywheel that the crank position will read and send out a square wave. I tapped into the factory crank sensor that is already installed on the truck and it produced a good square wave signal but when RPM was increased the injection time was decreased on the natural gas ECM. This is what leads me to believe the natural gas ECM it's looking for duty cycle time and not the number of pulses to determine injection timing. Getting to the point here I think my best option is to install another crank position sensor and add some nuts on the flywheel for it to measure but how can I get that signal to produce a longer short to ground(duty cycle) when rpm is increased. Any ideas would be much appreciated. I have a fairly decent understanding of electronics but I'm surely not a electronic expert on a component level. Thanks in advanced

 

[duke37]

I don't think I can help with the electronics, however, I wonder at the safety of welding to the flywheel. I would not like half of it to go for a flyabout.
Do you crack test the welds?