acy76--

The early termination of the glow interval (with the glow lamp staying on) happens in my C223 p/u when one or more glow plugs are open. I suppose the 4JB1 plugs could be enough higher in resistance to cause this but it doesn't seem likely.

I don't think the disconnected temp sensor will affect this as the controller sees the disconnected sensor as a cold engine, so glowing should happen.

I suggest removing the glow bus and checking each plug for normal resistance of about 0.2 ohm.

I assume that you have the short busbar resistor in the glow current feed. This resistor senses the current and reports back to the controller. When the glow current falls below a set value of about 70 amps the glow interval is terminated. This why having a plug out immediately terminates the glow interval.

Hope this helps--

Paul