On the left of the picture is a plug in the intake manifold which looks like it has an electrical connection stud on it but is also posdsibly thermal or baropmetric in nature. I simply don't know. That line is connected to what looks like a solenoid on the bulkhead, the other port is connected to the injection pump overflow 'fitting', probably the always-open part of the valve. I'm keeping this system IF it is useful, otherwise it comes off like the fan-clutch in my other posting today. And just like with the other posting, if I had the manual that would help a lot, but I don't.
Looks like it is intake glow-flame plug
That was quick, no more mystery! Never heard of those but looked it up and there's the exact replacement piece in milions of copies. Thanks. Actually, this reminds me of a new type of search I can try, an image search, in this case it probably would have worked. Not sure if I'll keep it though.