I'd like some opinions on my problem before throwing unneeded parts at it.
The '89 TPI in my Monte runs well until it shuts off as though the key had been turned off. There had previously been at worst an occasional 'hiccup' but this year it's gotten to be a real attention-getter. It will now shut down long enough to see the tach needle drop to zero. (With the motor is still turning, stick car.)
I've swapped distributors several times to little or no effect. The most recent code was 42, spark timing circuit.
Whatever is going on is getting worse. It recently shut off while driving though town and wouldn't restart for nearly an hour. Today at home, it's shutting off while idling about every 30 seconds. Not going anywhere like this...

Relevant info:
Howell engine harness
Mallory coil, no spare on hand until tomorrow