Coil wire
 

Hi Gents

What size wire best from resistor to coil?

Re: Coil wire
 

Not trying to be "cute" here, but you can NEVER go too big on wire size. #14 or #12 stranded ought to get ya down the road! DD

Re: Coil wire
 

TY DD and I do think your pretty cute:)

Re: Coil wire
 

Little more help needed. I can’t determine the color of wire going to the coil. Under dash on resistor it’s clean and easy to see wire color. Looking at the wiring diagram... am I correct it’s the solid red wire going from resistor to coil?

Oh it’s 39 coupe��

Re: Coil wire
 

Assuming you're talking '39 or '40 Ford, I concur.....RED between resistor and coil! DD

Re: Coil wire
 

I thank you again Sir!

Re: Coil wire
 

Sorry for the lag. As mentioned, I am suspect of a bad coil wire. You see any issue with: Running a new #14 wire right on top of existing wire?

Re: Coil wire
 

Don't see a thing wrong with that. But before you go to all that trouble though, have you tried ohm'ing that existing wire to see if it in fact shows continuity (conductivity), or if it shows an "open" (non-conductive)? DD

Re: Coil wire
 

DD thanks. The problem is intermittent.

Re: Coil wire
 

While a broken wire could produce an intermittent problem, I suspect source is more likely the ignition switch or a loose connection. I have heard of guys playing with the ignition switch toggle to make continuity to get home.

Re: Coil wire
 

Thanks and I agree with your logic.

I’ve already replaced the ignition switch. Got new Skip coil with a tested condenser from him. Also rebuilt distro from Bubba.

I’m fairly sure it’s not fuel. I have had fuel tank professionally cleaned and replaced all of the fuel lines.

This wire is the last item on my list of possibilities.

Re: Coil wire
 

Have you done the basic fuel vs. spark test?

When the intermittent problem is occurring, look down the throat of carb and move the throttle to see a squirt of fuel. If you see it, you know there fuel in the carb.

When intermittent problem is occurring, remove a spark plug lead and hold end near a ground, to see if you are getting spark there.

Re: Coil wire
 

Yes to both. The issue only seems to happen when driving/cruising 45-50 mph. Car will buck. If I floor it it seems to go away. If I stop at light it idles fine.

I added the #14 from resistor to coil. I’m really hoping it resolves the issue.

Re: Coil wire
 

OK. If only happens when at high speed, the plot thickens. "45-50 mph. Car will buck"

The only thing that comes to my mind is possibly a sticking valve. Here is an easy-to-do try: Marvel Mystery Oil. When I was dealing with a sticky valve, MMM in the oil did nothing. But MMM in the fuel cured the problem on the first drive. I was a skeptic of snake oil fixes, but now I'm a born-again believer. Sometimes (rarely) a chemical treatment can actually fix a problem.

Let us know when you find the cure so we can all learn from others.

Re: Coil wire
 

Having just spent the last 5 months trying to fix a similar problem make sure that the fuel bowl on the pump is not sucking air that was what mine was doing and exactly the same symptoms

Re: Coil wire
 

Thanks for that, but I removed mechanical pump. Only run airtex electric pump.

I’ll buy a bottle of Marvel mystery oil for gas. Can’t hurt:)

Re: Coil wire
 

It was likely a 16 gauge wire back in 39. The old cloth covered stuff doesn't hold color well after 10-years or so they all look like straw unless they were covered with loom, tape, or something of that nature.

Re: Coil wire
 

One of the drawings calls out #16 on later years.