Issues with 74 Dart
Could a bad pick up coil in the distributor cause this problem?.
Yes. Do a general inspection of ignition.
Remove ECU clean the mounting flange and firewall and install with star lock washers. Same for regulator. Both MUST be grounded
Remove the ECU connector, the ballast connectors, and the dist connector, and inspect for damage/ corrosion. "Work" them in/ out several times to scrub clean and remove oxidation, and feel for tightness of fit.
Check the reluctor/ pickup or strike damage, rust and debri. Set the pickup gap with a brass feeler to .008" (inches not metric) You could buy brass feeler at O' Really
Check dist. for shaft play.
Get yourself a spark gap type spark tester so next time it fails you can jump out and check right there
idle problem:
The idle mixture screw adjustment works like this:
One direction (Rich) does not increase idle.
The other direction will cause idle to decrease and die is not careful.
This could be somewhat normal on some carbs.........newer smog carbs especially don't have much idle mixture range. But it ALSO could be, if you can't get a good idle, that the idle circuits in the carb are partially plugged, or that you have a vacuum leak somewhere.