Ignition

[coralcoupe1993]

I have a big block that is fowling plugs every 25-30 miles. Has anyone had an ignition system what didnt have enough spark out put. I am wondering if the stock Ford ignition isnt enough spark to burn all of the fuel. Think an an aftermarket dist, coil, box would help? The ignition is a 1964 390.

[Chris00GT]

I'd buy a spark tester to see how stong your spark is. You may have a bad coil. It's a cheep little tool that allow you the distance that the spark can jump to give you an idea how stong it is. My guess though it's more a carb issue with the car loading up. Most times you really only need an ignition if you have a high compression engine or some kind of power adder. Usually stock parts in good working order are enough.

[coralcoupe1993]

I'd buy a spark tester to see how stong your spark is. You may have a bad coil. It's a cheep little tool that allow you the distance that the spark can jump to give you an idea how stong it is. My guess though it's more a carb issue with the car loading up. Most times you really only need an ignition if you have a high compression engine or some kind of power adder. Usually stock parts in good working order are enough.

Sounds good. I tried a different coil even put in a Malory Dist I have... Same issue. The carbs are dailed in. I am running a stock plug wire too.

[somethingclever]

SHould have about 4 volts at the coil if stock setup and points. 12volts if electronic setup. Points gap around .017" IIRC. Setup about 14 deg initial and 35 total all in by 3k rpm. That'll get you ball park.

If that is in check..i'd check for a stuck needle/float in one of the carbs. Make sure fuel pressure is around 5-6 psi.

And you thought 3 carbs were going to be easy...LOL :sticktonge:

[Domination]

The spark doesn't burn the carbon off, it just ignites the air fuel mixture. Its that mixture burning close to stoich that will keep your plugs clean. A more powerfull spark might help to get your plugs more thoroughly fouled, but won't fix your overfuelling issue. Unless of course your oil fouling them. How can you have your carb dialed in if you indeed do have a ignition problem. I'd test that sh*t with a skrew driver in the end of a spark plug wire. Hold the shank about half an inch away from the head and have somone crank it. If it jumps that gap, then fix your carb.

[coralcoupe1993]

The spark doesn't burn the carbon off, it just ignites the air fuel mixture. Its that mixture burning close to stoich that will keep your plugs clean. A more powerfull spark might help to get your plugs more thoroughly fouled, but won't fix your overfuelling issue. Unless of course your oil fouling them. How can you have your carb dialed in if you indeed do have a ignition problem. I'd test that sh*t with a skrew driver in the end of a spark plug wire. Hold the shank about half an inch away from the head and have somone crank it. If it jumps that gap, then fix your carb.


Sounds good. The carbs were tuned on a different motor. I really think this thing has too weak of a spark.

[coralcoupe1993]

I fixed this issue. Adjusted the trips to factory 406/405hp specs, put an MSD box, new plugs, and 8.5mil wires. She is running SICK (for a 4040 Lb car)!