big cap upgrade problems

[rommel1940]

So the other day I got my new coil in the mail before the cap and wires, I installed the coil and incould tell a difference, it was running stronger. Well today I installed the cap, rotor, plug and wires and now my car is running crappy, it will idle fine, but is very hesitant when accelerating. I don't have a timing light, so I tried to make adjustments, and I could never get it right, now im frustrated again, I just got the carb right and now this bs.I know I have the firing order correct.I put autolite copper plugs in there, it had champion platinum before, I don't think thats issue.

[rommel1940]

It was the spark plugs, I can't believe it.Well its running good now, never heard of a issue like that
 before

[vangremlin]

It was the spark plugs, I can't believe it.Well its running good now, never heard of a issue like that
 before

What was the issue with the spark plugs or do you know?  Did you just swap back to the old plugs?  I think when I did this upgrade I changed the gap to 45

[mudkicker715]

Yup gap needs to change.

[eaglefreek]

I've had them drop spark plugs on the floor at the parts store and then try to give them to me. I told them I don't want those and you might as well throw them away and they looked at me like they were confused.

[rommel1940]

The only problem Was the new plugs, I gapped  them correctly. Even regap them, but as chanceI threw the old ones back in and the car ran great, only change.old plugs champion platuim, new ones that didn't work autolite copper.Its thst werid or what?

[rommel1940]

After that ordeal, I didn't change my stock plugs gap at .35, would it really make a difference to gap them to .45? stock is .35

[johnbendik]

I think that's one of the reasons to do the 'big cap' upgrade: to use that extra voltage to make a 30% bigger 'fire in the hole' to set off the fuel charge.

That being said, you probably don't want to go much bigger than .45.  I used a PerTronix 40511 Flame-Thrower 40,000 Volt 3.0 ohm Coil and set my plugs to  .50, but it started to ping a bit and would sometime diesel (continue to run after the ignition was killed).  The bigger, hotter spark generates more heat.  I ended up going with a slightly cooler plug (Champion RC12PEC5, also a platinum plug), and everything seemed to balance out and run really well.  The big cap upgrade was one of the best upgrades I did to my Eagle; it solved a bunch of drivability issues and just felt a little stronger and smoother overall.

Good luck with yours,
JB

[rommel1940]

Thanks, sir