I have a '79 124 that stalls at idle after running for about an hour. I have replaced the coil, ignition module, distributor pick-up and carburator.
This problem started about 3 yrs. ago and I can't seem to resolve it.
I've moved the ignition module to a separate heatsink and replaced the coil with an ACCEL Superstock coil that has the same primary and secondary resistances. The carb is a brand new 34ADF from Redline. I also replaced the mechanical fuel pump with an electric one about 4 yrs. ago. The symptoms are that I drive for an hour or so and then when I come to a traffic light and take my foot off the gas it stalls. Just shuts off. However, it will start right back up every time! If I hold my foot on the gas and keep the idle high it won't happen. Has anyone out there experienced this problem? Or does anyone have any good ideas on solving it?

my wife's has the same problem
no clue what it is
chris

I had a similar problem and traced it to a weak alternator (bad diode). It would not put out enought "juice" to keep the car running (coupled with an old battery). Replaced the alternator and the problem went away.

A local auto parts store can test the unit for you while it is on the car.

New alternator 2 years ago. no change except lights were brighter!
Talked to a local foreign car mechanic and he said to change the fuel pump, those electric ones get tired after a couple of years. Just changed it Sunday and haven't driven it long enough to tell if it made a difference.