This was a very high-stress but tons-of-fun project that involved an enormous 12-liter heavy duty diesel engine. My client got pinched big time when the supplier of hardware really botched the project. I picked it up and ran with it! This was really strange and really fascinating stuff. We were injecting a fluid into the combustion chamber of a running diesel engine through the diesel injector, along with the diesel fuel. And we were able to inject some fuel, then this other fluid, then more diesel. And where in the injection event that this other fluid was injected was a variable and controllable! That was really fun! But it was only fun after I finished it and installed it. My design and hardware performed flawlessly!