72 350SL Stalling
 

I have a beautiful 1972 350SL that is making me crazy. 130,000 miles After about 20 to 25 miles, and usually on hot days, it will start missing and then stall. Will not start. After 20 to 30 minutes it starts right up and runs like a champ. This problem became very consistant. I have replaced fuel pump and filter, coil, points and condenser. Finally got it to act up at my mechanic and ony 2 injectors were firing. Replaced the trigger points module and it has purred for the last month. The other morning, (cool morning), after 15 miles it shut down immediately. No missing or rough running as a warning, just like someone turned the key off. Would not start. Waited about 20 minutes and it fired right up and has run perfect since. From what I have read, ignition module? The one inside the fender? Thank you for any help, I need it!

I might suggest the trigger points, they are located in the lower section of the ignition distributor. Two versions exist, one with a pigtail and one that connects to the distributor. Double check the center shaft to ensure you do not have excessive runout.........

Trigger points replaced just a month ago. It is the one with the pigtail connecting to the distributor. I did check the distributor shaft and it feels tight, no side movement. Thanks for the help. Anything else?

May be a ballast resistor, an ignition switch or an ignition module. I would probably perform a voltage drop test between the battery positive terminal and the ignition coils power supply (terminal 15). The outcome of that test would dictate my next move.

Suggested Test
 

Not sure under what conditions to perform the recommended test, but this is what I did. From battery + to coil (#15), and from battery to chassis ground, without car running, was 12.42 volts. With car running, same test points, 13.27 volts between ground, 11.8 volts between battery/coil. The ballast resistors, which I hope is the 2 ceramic blocks beside the coil, read .7 ohms, silver bracket, .6 ohms on the blue bracket resistor. I see where blue should be .4 ohms and silver .6 ohms Silver bracket one look fairly new, blue one looks old. Where do I go from here. Thanks