I have an 82 12a in my Triumph TR7 the P/O did such a crappy job that the thing didn't even run. I went through it and got the car running and have been driving it for a few months. Now I'm getting annoyed with the way the car is running. It has an intermittent miss. I originally thought it was because of the he I module on the trailing side. I took it out and I'm still getting it.its more pronounced around 1500rpm. It almost sounds like the ignition is randomly cutting out for a split second. First things first how heavy of a wire should be feeding the coils and ignitors? Mine has 16 gauge which I think is too light considering its 2 coils and 2 ignitors. I hooked my meter up to the power feed on the coil then to a ground on the body with the car running it was only 4-5 volts. But with the ignition on and the car off I have 12 so I'm thinking its pulling too many amps and the thin wire is creating too much resistance. Otherwise could it be a failing ignitor? I changed my cap and rotor and if I rev the engine over 5000 rpm between shifts I noticed its nicking

 

Sorry accidentally sent the post. I meant to say if I rev the engine to 5000 rpm or above the rotor seems to be nicking the distributor cap so I may have a sloppy distributor? Do these distributors benefit from being shimmed between the body and the gear?

 

Try a different set of spark plug wires. Years ago, I had a similar issue.

 

My wires are kinda new I only put them on in June roughly 4000 miles ago. What brand do you reccomend? What's funny is I tried pulling the leading wire off on each rotor and it still sounded the same.

 

Is this a stock ignition setup?

I ask because of this phrase "because of the he I module on the trailing side",
which I read the "he I" as HEI maybe.

 

Its semi stock. Its all factory but the ignitor went out on the trailing side, I got screwed twice on eBay with bad ignitors, and I didn't have the money at the time for a new $300 ignitor so I used the HEI module to trigger the trailing side. The leading side is still the factory ignitor. Which I'm wondering if its on its way out. Its been running worse and worse over time. I'm debating in using the HEI module on the leading side too.

But I wanted to make sure my electrical system was done correctly before I just go wildly changing parts.

 

Do a search for DLIDFIS. It might be right up your alley.

 

Ive looked at all that before, but right now I need to know what gauge wire should be feeding the coils and how many amps it should be pulling

 

The factory used what looks like 12 gauge on some models. Can't go wrong with that thickness if you have it. Or 14 gauge can work as it's a good factory size as well. Don't go thinner and no need to go thicker.

A stock J-109 ignitor can use up to 3 amps before it goes into what's called current limit mode.

A GM HEI can go up to 5 or 6 amps (depending on brand) before current limit mode.

 

Ok, I figure the coil probably pulls an intermittent 3 amps or so?

 

Does it only act up when its warmed up or hot? Seems fine when its cold or just started?

 

It misses a little when cold but gets worse when cold.

 

I meant it gets worse warm.

 

Classic symptom of the ignitor failure. They get worse a they get warm and finally will fail when
hot.

 

That doesn't sound right... Coils could be swapped / hooked up incorrectly. If you pull a Leading wire the car should stumble or run rough. If you pull a trailing it should still sound the same. I used 10awg when feeding my coils w 12V.

Once I was sure I had verified my coils were hooked up right I marked the actual coil T and the other L. It came in handy from that point foward as time can pass fast btwn wrenching sessions.