Please help, I need ideas.

Subject: 1987 300E, W124 chassis, M103 engine.
Problem: when cold, starts without issues, no misfire, runs smooth as can be, like it's brand new. Can rev the engine, drive it around the block, works beautifully...until it gets warm (>80 degrees C). As soon as it gets to running temperature (about 20 minutes), it chokes, stalls, and dies. Then while still warm/hot, it will not restart. Engine turns over (starter turns it over fine) but engine will not catch. Not until it's cool again. One hour later when cooled down, starts up and runs like new again.
Thinking it's a failing camshaft position sensor? But I reliably get 800-900 Ohms. Should I still just replace it and see what I get?
No fuel smell, no leak, I feel like I'm chasing an electrical gremlin.

Took it to a relatively young mechanic who couldn't figure it out and just gave me my car back.

Help! She's too nice to part out.

Thanks.
Cam

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1987 300e W124 M103 My baby.