I never had the pleasure of meeting him in person, but of course I spoke with him many many many times on this forum, and years before that on the Whoretex (I feel I should keep a few Jack-isms going
), and a couple times on the phone.
Back before I stopped worrying and learned to love my CEL, he helped me make progress on troubleshooting my Phaeton W12. I had reached a point where I was ready to park it in a bad part of town and set it on fire, and he talked me down. He said something to me, over the phone, that resonated with me and I remember to this day: "You can figure it out. It's just a machine."
I don't know why that broke me out of my loop, but it did. It worked on the part of my brain that had decided I was defeated, that it was an intractable frustrating unsolvable mystery of the universe, and moved it back into the domain of things that could be analyzed, tested, potentially solved. I don't know how to explain it better than that. I have worked on other problems years later, things entirely unrelated to automobile engines at all, and sometimes heard that voice again: "You can figure it out. It's just a machine."
From what little I knew of him, again not having met him in person, I don't think Jack had customers in the traditional sense of the word. I think Jack decided whether he wanted to count you as a friend, and if so, he was a great friend who would offer solid advice, and also sometimes he would exchange fiat currency for goods and services in a ratio he deemed fair at the moment. If you were not Jack's friend, he would not be doing business with you, and that was the end of it.
It's the eternal bane of Internet forums that tone of voice, that intent, that emotion sometimes does not translate well to the written word. That was often the case with Jack, who had his own unique style of writing. I don't know how there could be such a difference between Jack the online persona, who wrote automotive advice in the style of
Time Cube guy, and Jack the warm and personable fountain of knowledge I spoke to on the phone, but there was.
I'm sad that not everyone managed to read between the lines enough to learn from him, but glad that so very many did. I'm glad that Jack was a friend to me, and that I had the opportunity to learn from him. I'm truly, deeply saddened to hear of his passing.