1991 300e shuts off

[A Khan]

I hope someone can help. The car is 91 300E with 95K miles. Replaced the battery and coolant today, drove to a gas station and filled up with gas. After driving about 15 min the car shuts off in middle of the road and all the dash board lights lit up. Tried to restart (it cranked and cranked) several times with no luck. After about 5 minutes it fired up and once I reached the house it died again. Thinking maybe it's a vapor lock I opened the gas cap and the gas bullbles out (it was 99 degrees outside). After waiting about 5 minutes restarted it again and pulled into garage. This is what I then did to troubleshoot:

1) Cleaned ICV
2) The distributor rotor looked fine
3) Checked OVP and it was fine. Just in case I replaced with a spare one I had.
4) Checked spark plugs and they looked fine.

Started the car and it fired up immediately. Drove around the neighborhood several times and it drove fine. I then let it idle and it shuts off after 5-8 minutes. Before it shut down the idle was steady 600 rpm and then it went down to almost zero and then immediately shot back up 800 and after a few minutes it shuts down.


This is what was done about a month ago:
Had fuel pumps and fuel filter replaced by the dealer.
Transmission filter and fulid changed by the dealer
Had all four tires replaced and tie tods replaced

This new problem stumps me and I am reaching a point where the car seems to be taking me to a bottomless money pit. Thanks.