66 Olznut

I recently replaced all the ignition parts in my car as well as adding a Perlux Ignitor. The problem is that you can hear and feel an occasional miss and when I grabbed the distributor to adjust the timing, I got zapped. Rev it up and the missing gets worse. The first cap I bought was an MSD cap but noticed it was cracked up on taking it out of the package and I returned it and got another. It looked fine but could I have possibly got 2 bad ones in a row? I replaced the plug wires after as well, no change. I'm leaning towards the cap again but I'm open to suggestions. Help!

oldcutlass

Double check the simple things first, wiring order, make sure plug wires are fully seated at both ends, timing settings, etc.

TripDeuces

Full 12v to the Pertronix?

66 Olznut

I checked all the simple stuff and it's fine.

Yes on the pertronix having 12v.

oldcutlass

Did it miss before going to the pertroics?

66 Olznut

Yes, it helped smooth it out a bit.

oldcutlass

Did you replace the wires? The reason you got zapped is there is or you created leakage around the rubber boots or they were not seated. I would look down into the carb while the engine is idling and see if there is fuel dribbling. What did you set your timing to?

m371961

If you are getting zapped you got a electrical leak. fire it up in the dark and spray cap with a water bottle mist.

66 Olznut

Well, eliminate the cap, I replaced it and no change. Didn't mess with the timing to see if I got zapped but the stumbling still there, it starts at just under 3000. One other thing, last time I checked the timing, it was bouncing around a few degrees. One of the guys I work with says the distributor springs and/or weights might be weak.

droldsmorland

What is the base, vacuum and centrifugal timing events set to? You need a set back timing light to obtain this data.
A vacuum gauge is key here too...Use a vacuum gauge to adjust the air/fuel to obtain the highest vacuum reading. Then do it again adjusting the timing to obtain the highest reading. Then go back in forth between the two until you have both settings yielding the highest vacuum reading. Road test. Stumble still there?

Verify zero vacuum leaks. Typically if the air fuel adjustment screws have no effect on the vac
gauge readings this indicate a vacuum leak.

Timing basics...As an example: E/G block 400s or an F block 455 street timing is... 10-12* initial, warm at idle with a properly adjusted carb and the vac can blocked off. Then with the vacuum can hooked to a manifold vacuum source it should bring in more timing say timing, 10-12* for a total of 20-24 at idle. Verify the vac canister is working and not leaking. The rest is the centrifugal timing. This number added to the last two specs will equal your total timing event of 36-40* all in at ~2800-3200 rpms. These specs are set according to gas quality and octaine level, altitude above sea level and your driving manors. Adjust accordingly.

Did you swap out rotors for a known good one?

Verify that the wire coming from the coil neg up through the distributor base is not chaffed and grounding out on the breaker plate when the vacuum advance moves. This is common.

Also verify your engine block has a good clean ground path to the battery via the large secondary battery negative cable and a ground strap from the block to the body...firewall.

If all this checks then we'll move on the the fuel system.

oldcutlass

You need to set your timing and your carb. Like I said earlier, look into the carb with the engine running and ensure its not dribbling fuel.

66 Olznut

Very good information, thank you very much, I'll check it out this weekend when I have more time and let you know what I discover.

The carb was just rebuilt by Sparkys last week and was doing the same problem before.

Octania

The carb was just rebuilt by Sparkys last week and was doing the same problem before.
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That tends to rule out the carb then

Spark plugs and gaps?

lemoldsnut

Poor plug wires can do this also. Even good ones can be bad

66 Olznut

Plugs are new Autolite 86, gapped at .035, I have a new Pertronix Flame Thrower coil. Nothing changed when wires were replaced. I just purchased an adjustable timing light, vacuum gauge and some other tools, notes will be taken and results posted. I will get to the bottom of this.