Truck dies

New to the me 87 mazdab2600 4x4 5 speed. Runs decent. Dies when driving at times. No rhyme or reason when it does though. Aftermarket Weber Carb. Any thoughts? I have been told maybe valve and seat?
Please help

Does it start right back up? Ignition components like to act up when they get warm, and usually work fine again when they cool.

Yes it does start right back up after up a few minutes. Just weird. Son drove from practice to his grandparents and home and never died. After school he has to drive about 2 miles to practice and it died twice in that amount of time.

I'm thinkin' that the first thing I'd check would be the electrical part of the ignition switch. Symptoms are the same as I had with my '88 B2200 15 years ago. Your Weber carb is not a factor in this (I have one too).

The circuits for the starter are different than the "run" circuit. The electrical parts of these switches typically go bad like this at about 20 years or so. Next time this happens, do not switch off the ignition, just pull over, open the hood, and see if you have 12 volt positive to the coil positive terminal. If not, it's the switch. You could temporarily jump to the parking light circuit to the coil positive, then turn on parking lights to run the truck and then replace the switch.

And how does one do that?

Use a multimeter in the 0-20 volts DC setting to check voltage at coil positive with the red voltmeter lead. Practice this before you set off so you know how to do. That's better than using a 12 volt DC test light, in my opinion. The other end of the test light or multimeter black lead goes to bare metal on the engine or body (the ground, or negative). There should be 12 - 14 volts there if the electrical part of the switch is making contact, zero if not.

Question: does the radio go off as well when the engine stalls out?

Yes the radio does shut off. He says it's the first thing that goes.

When my ignition switch electrical went out, the radio circuit also shut off at same time. This went on for about a week for me, no Internet to help me back then. So that's a good clue !!!! Pay attention.

Thanks for the info!

I PM'd you for your E-mail address, I can E-mail a wiring manual (1992, but similar for most years/models).