86 740T, 161K. Weird problem. In the morning, car cranks on first turn, engine runs so smooth you hardly know it is on. However, over the last week the last couple of times that I've driven it kind of hard (extended driving @ 65+ mph), after I let it cool down and turn it off, when I restart it within 2 hrs or so it has to be cranked twice to turn over, and it runs with a noticeable miss, which varies from slight to so bad the engine has shuddered, vibrates hard and sometimes cut out. I've done a super major tune up over the past two months (engine wires, distributor/cap/rotor/plugs). Fuel injectors/o-rings were also replaced). At first I felt like a vacuum line that might not be seated so that when things got hot and hectic under there air flow wasn't quite right, so I checked all of them and they all were secure and tight with no [obvious] leaks. Now I'm not quite sure where to proceed. Any thoughts?

You were exactly right. Took it out, cleaned it up good, and cleaned it some more and the first time I fired it up I could tell the difference. So I took it off again (to familiarize myself with it even more) and cleaned it one more time for good measure and it seemed to run even smoother. There was also a cable running to the bottom of the distributor that was also badly frayed and had been soldered on all three wires, so I checked those and retaped them, made a slight adjustment on the distributor alignment and now you can hardly hear the engine running with the hood shut closed.

Thank you so very much.

I have identical problem. If you find the solution,
please post it here.

This must not be a very interesting problem. No responses so far. I will tell you that I have changed the air filter, checked the voltage to the fuel injectors, had my wiring harness changed (within the last two months). The problem just seemed to appear one day. What is confusing is that it only happens after the car has been run awhile, but never when the car is cold. Cranks and idles smoothe in the morning, or after it has sat (cooled down). I'm going check (with my limited knowledge) the power stage, and change the plug wires. What might be a concern is that my distributor failed about a month ago and I replaced it with one I bought off of ebay as a spare (the seller said he had only had it in his 740 for about three months before the car got totalled from a rear-ender). So I am now wondering if it might be a faulty distributor, but I am also thinking that if it were the distributor it wouldn't make much difference whether the car was cold or hot for it to misfire or idle rough. But then, what do I know? . . . should I come across a solution though, I will definitely post it for you.

I'm having the same problem -- only misses going over passes,etc under load. Called Bosch, suggested an O2 sensor failure (mine is original at 160K). They said at high temp could send wrong signal. Checked w/voltmeter and it wasn't working (easy to check but might not get load conditions). Found one cheap on internet (106) so I'll try that tomorrow. Like you,I've replaced a whole ton of other parts already trying to fix this problem.