John, no resistance values for it. It's obviously a variable resistor or "pot", but if the voltage goes up steadily as you open the air valve, then it's probably not the culprit.

I reread your posts, you say the car began to run okay for awhile after new plugs? Then started to mess up again? That's probably not due to you installing resistor plugs - most things I read indicate the resistor plugs run fine for quite awhile (or forever) but may damage the ignition eventually. I ran some in mine waaay back, before I was told of the potential problem, I saw no issue.

So, "maybe" it's fouling the plugs quickly, you said smoke was coming out.
If it smells funky, could it be coolant?
How about this.... engine got pretty warm in the slow traffic, the old head gasket gave up (this is VERY common issue on 103 engines) and it's allowing some coolant into one or more cylinders. This is making the engine miss and causing all sorts of starting/running issues.
Why don't you pull the plugs again and look for any clues on them?
Look for white smoke.
Look for bubbles in the coolant reservoir.
Do a compression check.
Look for milky oil.
Look for coolant leaking externally through the head gasket back by #6 spark
plug.

If it's a head gasket, you should be able to find it. And you better fix it fast if coolant is getting in. The head is Al, the block is iron, so the head gasket scrubs itself to death from expansion about every 100k miles on these
engines. Not too hard to fix.

Let me know what you find; if you need to redo the head gasket, I can walk you through it.

Of course, this is all guesswork on my part, it may be a dis-combobulated Flamerstam or something.

DG