Topic: Ignition Issues

[badazblu]

 
I've got a '66 289 with all new ignition parts: Flamethrower coil; Pertronix Ignitor module; new cap and rotor; Ford Racing 9mm 'cut to fit' plug wires and autolite plugs (gapped .005 over) plus the distributor has been recurved. I was driving at highway speeds last week when the engine suddenly started running very rough (almost like it was only firing on 3 or 4 cylinders). I found that the coil had cracks in the top or 'cap' area around the +/- terminals and oil (coil is oil filled) had seeped down the sides. This is strange as I added this coil during the 5 year resto I'm just now finishing up so it's literally brand new. The ignition was left in the 'run' position several times during numerous wiring episodes including once over night which ran the battery down. I assume this had something to do with the premature coil failure. I just finished replacing the coil with the hotter Flamethrower II and decided to replace the Ignitor with the newer Ignitor II module as these are reccommended to work together for peak performance (plus I don't know how old the original Ignitor module is as it was installed when I bought the car). Started the car again and it ran perfectly on high idle for about 10 seconds then gradually started missing and losing rpms until it died about 50 seconds after starting it. Almost like it was fine until everything in the ignition heated up. When I tried restarting it right away without letting it cool down it ran the same as it did when it died. It kind of clears up as rpms are increased above 3000.
     I tried disconnecting the 140 amp alternator, wondering if maybe it was overpowering something-same problem; talked to Pertronix & they suggested bypassing the ignition to coil wire, thinking that maybe it had surged in resistance-same problem; checked spark to all 8-good. Anybody got anything? Thanks

[Jeff73Mach1]

did you reset the timing after adding the new Ignitor II module?  Does that module require a specified air gap for the pick up and if so did you set it and verify the setting?

I think your coil failure is just one of those things that happens over time and you didn't cause it, though leaving the key on (engine not running) will burn one out over time but it won't crack it.

Check that your distributor hasn't turned.  What you are describing almost sounds like the engine timing is retarded and when the mechanical advance kicks in you get enough timing to smooth things out.  On fast idle you had just enough advance to run okay when it slowed down and the weights in the advance allowed timing to return to base your engine timing was too far off to maintain a decent idle.

or you have a massive vacuum leak

[Soaring]

First of all, you need to regap those plugs.  They should be gapped at 0.034 instead of 0.005.  You could even open them up a tad more with that pertronix ignition.  Try that, then get back.  A vacuum leak will make the engine run rough at idle, then smooth out at higher RPM's.  Listen for any hissing and locate the leak if there is one. 

[Jeff73Mach1]

I think he meant he went .005 over the stock gap.

[Soaring]

Then that's good. 

[badazblu]

I checked timing and it's sitting at about 24 degrees btc at idle which is where the engine builder that cut my cam set it. It's that far advanced due to the altitude here in Denver. Also, when I installed the new Ignitor, it comes with a piece of plastic that is .030 thick that you use to set gap between the module and the magnetic collar. Funny you should mention vaccuum leak as I sprayed starting fluid at the base of the carb and the motor surged significantly. Also, I had the aircleaner off and could hear what sounded like a cat spitting up a hairball-kind of a K..K....K.K...K.... for lack of a better analogy. I've also been dealing with some overheating issues though I can't say they're related to this problem.

[Soaring]

Yeah, that vacuum leak will do it every time.     Overheating can also be caused by the timing being set too high as well.  24 sounds like an extreme high setting even with a special cam since the original is 6.  Consider backing down some on the timing and see if that doesn't help cure some problems.  That little .030 plastic thing is just a shirt sleeve gap setter.  You just have to get the Pertronix close for it to work. 

[Jeff73Mach1]

24 degrees!  Wow, I would be surprised if bringing it down to about 16 didn't improve your performance and driveability quite a bit.  Is that 24 with the vacuum advance disconnected and plugged?

Some carbs use a contolled vacuum leak at the choke to keep the choke housing from melting.  Make sure your "leak" at the carb base isn't from getting fluid in this small port