B2200: Wrong Ignition Coil?

@ phils2200, glad you got the right part identified.

Coil: Wells C819G (wrong), C1114 (correct)
Symptom: Misfires on hot days under heavy load (uphill)

Your symptom is only under those conditions? Idling and straight runs are not problematic?

I didn't notice much of an improvement with the EFI setup to be completely honest, I noticed more of a gain (still slight) with a carb setup. What the blaster coil allows you to do is to run a bigger spark gap, allowing for more complete combustion. IIRC, I ran .010 larger gap when running the blaster 2 with Accell 8mm wires.

Ya, runs good otherwise. Only thing I can think of is the coil breaking down or maybe a fuel vapor-lock problem, but I doubt the latter. A coil is pretty cheap and easy so I thought I'd try that.

Follow up: Put the C1114 coil in (a perfect match - same markings as my old one) - runs perfect so far. I'll see how it does this summer.

Some vehicles require a ballast resistor. On the old Chevys it's because the ignition switches had a design flaw that allowed electrical current to backfeed to the starter. The resistor burned up just enough current to keep the starter solenoid from fully energizing.

Our Mazdas have a well designed high-current switch that isolates individual circuits, so the above scenario doesn't apply. I wouldn't worry about your new coil.

I think you're talking about a different resistor - maybe.
That's not what I was told. I understood the ballast resistor in many of these old vehicles was bypassed during start to get more voltage to the coil when cranking (due to voltage drop caused by high current load to starter motor) and then the resistor was in the circuit during normal running to reduce the voltage going to the coil. Without the resistor you might burn up the coil. Just what I heard. I haven't confirmed with wiring diagrams.

I had an intermittent engine stumbling issue about 8 years ago, and my stock coil was leaking a little around its seam so I just got a replacement at O'Reillys. That did NOT solve the stumbling (it turned out to be ignitor/pick-up), but I still am using that replacement coil. 1988 Cab Plus B2200, MT.

Ya, I replaced the igniter module in mine also a few years back. It failed completely - no spark. It was a cheap Cardone unit. Its possible that's failing when its hot and under load. Thanks for the idea.

I hate to keep everyone on the edge of their seats , but I won't know 'til next summer if mine is fixed or not. Excuse me now, gotta go make myself an espresso...

Ordered a new Capacitor/condenser. I was told by many (& have seen this on a few forums) that the little black box that goes to the + side of the coil was to prevent radio noise. It is in fact an ignition condenser. It is in the wiring schematic in the Haynes manual. I have heard many of you say your truck runs fine without this connected. But I have heard a few say that they have sluggish power & misfires with out it. My plug wires say "Radio Suppression" too...Does that mean they are there to keep my radio reception clear? I don't think so. I do however appreciate all of the tips & advice. You all have helped me go from a non-running truck to a yard driver. Dying to get it on the road, but at least I can move it in the yard.