Hello Scotty, Beam me up!

I have a '93 BMW 740i M60 engine 186,000 miles.  It randomly shuts off the engine when I am driving.  No codes.  One owner.  I put the spare down on the rear and it is not the same brand tire or size as the other 3.

It seems to happen when I am under power (cruising) and then let off the throttle to coast.  After it cools off for 45 minutes it restarts easily and runs.  Sometimes for 2 hours sometimes for days.  I took an 800 mile trip and had no problems on the highway or the destination city Albuquerque.  But back in El Paso I start to have these issues. Engine idles smooth, accelerates with good power and doesn't smoke.  Water temp is normal, never overheats, but aux fan is not running.  I use name brand premium gas only.  Oil is changed regularly.

I changed the mass air flow sensor, idle control valve, cam position sensor, crankshaft sensor, fuel pump, fuel filters, intake air temperature sensor, throttle position sensor.  I wonder if the automatic trans speed sensor and wheel speed sensors need replacing.  Also I heard that the water temp sensors could be the reason the aux fan is not running.

I am at my wits end.  Maybe the ECU is getting hot.  Need an experts advice.

Thank you so much for your suggestions and your youtube channels, they're great!

Bob Beemmer