ok....so.....the other night, was going to head to san francisco for a dinner date, had my phone plugged in to the usb charger in the cig plug. well about 5 miles from home, i smell burning electronics, my charger had burned out..figured eh... no biggie. bout a mile later the fun started. my engine with now 3000 miles on a rebuild and running strong is bucking hard and stalling. i eventualy got it home and immediatly started to check the fuel system thinking thats the issue..nope, changed the filter, checked fuel pressure, checked the carb... now this is a 1987 mazda B2000 with about 195k on the clock and about 3k on the rebuild. i replaced the battery, the alternator and the O2 sensor for the hell of it...still does it, runs better with the new battery and alt, but still bucks and stalls...usualy after 10 to 15 minutes of driving. does it in town, on the highwaym, doesn't matter. runs fine, cruises great then bam...stall. i did check all my electrical connections and are all fine. my ignition switch is crapping out, but pulled it out of the tumbler and use a screwdriver to turn it. got a new switch on order. i need to figure this thing out soon since this is my only means of transportation.
i put an accel coil in it about 8 months ago, cap. rotor, plugs plug wires and vacuum lines after i put the engine back in, so those should not be an issue.

 

Questions:

1. When it stalls, are the warning lights on the dashboard on or off?

2. Have you ever replaced the ignitor and pickup inside the distributor? About a decade ago I had such weird stalling out and bad running issues with my '88 B2200, and the cause was the ignitor and pickup inside the distributor.

 

the icm was replaced 4 months ago due to failing the dwell side of the test at autozone. the pickup coil was replaced about a year ago. as for warning lights....no...not.....even the oil pressure light crap thinking bad electrical system.....

 

If warning lights and radio went out went it stalled, could point to bad electrical part of the ignition switch; those are weak on these trucks as they age. The one on my 1988 B2200 went out about 1996.

Also had bad electrical part of the ignition switch on my '98 Frontier.