1976 B210 Ignition issues

[bunny reid]

Hey all, been a long time since I've been active here.

 

I've had a 1976 B210 for about ten years. It ran fine when I got it, odd hiccup. 4 years ago it starting to have intermittent no start issues, still ran fine when it wanted to start. I'm trying to get the thing going now that it's been sitting and not ran for about 4 years. I neglected it for too long it seems.

 

My current issue is ignition. I'm looking for a little insight as its been driving me crazy for a couple days. Discovered weak, intermittent spark from coil lead, and decided to replace the following: Coil, Condenser, Resistor, Point breaker, Plugs & wires. Tonight when I left the shop I discovered only weak spark from coil lead when letting off the "Start" position; while engine turning still over briefly in "On" position but refusing to start. My understanding is there is two circuits for the condenser while either in "Start" or "Run". I cant figure out why Im not getting spark in "Start". Circuit testing found my neg coil lead has seemingly solid ground while disconnected from coil. Ground breaking and closing but seems a little spotty at condenser/coil terminal of dizzy (could be shaky hands with my probe). While neg lead is hooked up to coil reading about 7v. WTF? Potentially loose/weak ground in distributor? Coil resistances checked out. Resistor tested about 1ohm which is a little low, but I dont believe this to be source of issue, am I wrong? Resistor gets too hot to touch and makes me think shorted? I cant find a diode in the diagram and resistor is simple wire coil with no internal diode so assuming can be hooked up either way. Haven't opened the harness yet, diagram shows a capacitor that I'm going to check out along my way.

 

The brain teaser is the 3 pin connector for my coil leads and I'm hoping someone has a straight forward answer or can confirm for me. I have my 12.X volts on hot pin, and solid ground on my neg pin, but the third pin (blue wire to transistor) is reading dead (no voltage, no ground). My understanding of the wiring diagram is these leads go to "Ignition Transistor". Fuse is good. Havent tracked down wires from transistor to dizzy yet. Can someone tell me if the third pin is supposed to be dead with KOEO? Is it hot or neg KOER or in "start," something like that? Or should I continue following this wire? Diagram shows it leading to transistor-ignition switch-resistor. Any possible insight from a Datsun guru or someone who has solved a similar issue would be greatly appreciated because Im starting to get lost in the weeds as to which direction to head first. I am inclined to believe possible short at or in the transistor, or broken wire in circuit. All this being said I am not a points ignition expert in the slightest. My wiring seems to be accurate to the 1975 B210 wiring diagram. Only one terminal at distributor, so the common "Matchbox Dis." diagram found on the forums confuses me further, as I have negative control leading from dizzy (breaker) to coil, and haven't noticed any hot wires from dizzy to coil (possibly blind, ignorant and dumb). Car has been stored in garage for the entirety of it's life and isnt super corroded at main grounds.

 

I also haven't backpedaled yet and confirmed the new condenser isn't faulty which is a possibility. Leaning towards the transistor giving me grief. Did I mention I'm getting lost in the weeds?

 

Thanks for any response.

[datzenmike]

The '76 will have single set of points and a coil with a ballast resister. Forget the matchbox diagram the B-210 never had it.

 

The trouble with changing all those parts is... it didn't help because they were not the cause, and now there are new untested parts on the engine that are most likely inferior quality and may have brought their own problems with them.

 

What does (blue wire to transistor) is reading dead (no voltage, no ground). mean? What transistor????? Post a picture of this.

 

 

 Get an old spark plug and plug into the coil lead. Hold against the head or block. Turn the engine with the starter. Spark???? What do you mean intermittent? Sometimes no spark?