Well, spring is almost here - so that must mean it's time to order another ECM. That's not right, is it? I think I have something not quite sorted with my ignition.

My '68 Barracuda had an MP electric vac-adv ignition upgrade done before I purchased the car three years ago. All the usual suspects are there - including orange ECM. But every spring I'm replacing either an ECM or a pickup coil.

Could I have the wrong ballast value? What should it be (quality part number appreciated)?

I'm running an original 35 AMP alternator, have decent wires, Autolite 99 (edit: 66) plugs @ .040, good cap & rotor, digital VR1 voltage regulator https://goo.gl/dMEr9L, Pertronix 40011 coil, and have good grounds. The car ran all last summer but was starting to stall out the last day before hibernation. Trying to get ahead of the game this year and hopefully fix this crazy cycle.

Looking for some advice...
-Chris

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

The Mopar ignition components, notably the ECM, have been poor quality for quite awhile now. Do yourself several large favours all at once with the HEI upgrade(which also gets you rid of the ballast resistor altogether).

Take a careful look at your distributor in case the "upgrade" was done with the Mopar Performance kit (which contained a distributor with two lightweight springs that dump all the advance in just off idle—very much not optimal for a street-driven car).

I don't think there's anything such as an Autolite № 99 spark plug, and neither do they. You might mean 66. Autolite plugs = Chinese garbage. Stuff'll work better in a variety of ways if you'll switch to the extended-electrode NGK plugs linked in this post (and follow the distributor cap/rotor link in that same post).

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

"every spring I'm replacing either an ECM or a pickup coil.

Could I have the wrong ballast value? What should it be (quality part number appreciated)? "

Ballast Resistor Resistance should be in the .5 ohm neighborhood at 70 deg F on the coil circuit

A typical Chrysler Ballast Resistor part number of the 60's time frame (with points ignition) was 2095501 however since you installed a 70's electronic ignition system the Ballast Resistor of that time frame had a typical part number like 3656199 and two resistance measurements of 5 ohms on the control portion and .5 ohms on the coil side at 75 deg F.

If you have the ability to measure the resistance suggest you do that before spending $.

Since my Dart was subjected to the same issues with frequent coil & ECM breakdowns (every 2k miles) (plus distributor cap center electrode fracturing) and came across the "New Parts Quality Issues" suggest you do you another test before buying more stuff. Bring the 68 Cuda to one of the monthly year round Plymouth Colonial Region meets up here in the North East and we'll do the test for you or if your close enough to me in Tolland, Ct. I'll drive over and do the test.

The Spark Output test is done on the coil wire and for the mild mannered slant in your Cuda it SHOULD be around 3-5 kw if things are OK in your Secondary circuit. If your Cuda is experiencing coil wire voltages up in the 20 to 30 kw range then it's best to check for high secondary resistances in your ignition system. In every case on my Dart it was poor quality new parts. On a recent check of a friends 65 Cuda (with Petronix ignition system) the voltages had spiked and the distributor center electrode had fractured after only a few thousand miles.

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

Dan - the HEI makes logical sense for a lot of reasons, but I want to retain as stock an appearance as possible. Can I wire up a canister coil to the module? Is it the same wiring?

RE: 99's - oh yea, they are 66ers. Got that backwards - er, upside down. DusterIdiot sorted out the springs for me, so I think I''m in good shape with that.

The post references are quite informative, thanks. Hope this level of detail is in DD's book ;)
-C

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

DonPal - thank you so much! Glad to hear I'm not alone, your comments were valuable to me.

Since writing this post, my thinking is to get rid of the ballast all together and go with the FBO ignition box and a quality pickup/reluctor. Thoughts?

The car is down and out right now, but I'll run the tests you mentioned. Would love to connect with your group sometime - I'll connect soon.
-Chris

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

No, he didn't. He said the previous owner installed the MP ignition "upgrade", which wasn't available until well after the change from a dual to a single ballast resistor in the Chrysler electronic ignition system. The correct value for this resistor is 1.2 ohms at ambient temperature.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Also unreliable (and ridiculously overpriced, and hyped with all kinds of handwaving). You'd be paying big bucks to get no advantage over HEI and jumping out of the frying pan, into the fire.
I ran mine with a canister coil for years -- might not have been quite as optimal as an E-core coil, but it worked fine and reliably. If you want to be sneaky about it, use a Ford canister-type electronic ignition coil (like an Echlin IC-21) with its 2-wire connector Standard № S-583. This coil is specced to handle the kinds of voltages/plug gaps HEI is capable of running.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

" my thinking is to get rid of the ballast all together and go with the FBO ignition box and a quality pickup/reluctor. Thoughts?"

If you have another problem present like high secondary circuit resistance and you start changing the design (that do not address the problem) I'd be concerned that it could get confusing as equipment gets changed. Nail down the existing problem first & fix it before moving on to another system change that might bring it's own issues or just break-in adjustments?

In my case I found points ignition could take the beating that the HEI ECM & coil couldn't take while I troubleshooted and determined the source of the 65 Dart high secondary circuit resistance. So far I haven't put the HEI back while I'm verifying the issue is substantially corrected (putting on the miles). My daughter's 65 Dart with HEI is having the same issue and I found her Dart high secondary resistance issues to match what use to be present in my 65 Dart. So I'm monitoring two cars at once to see if the high secondary resistance fixes are successful before re-introducing the HEI back into my 65 Dart.

Based on Dan's info you might want to verify first that the Ballast is the correct one for your system (maybe the wrong ballast resistor is present?).

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

@SlantSixDan - would this be the correct wiring if using the coil you mentioned? https://goo.gl/Nnwpw2

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

Should be, yeah. Do make sure and check what springs are in your distributor, and your cap/rotor factors (read this whole thread).

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

AND - thoughts on using Pertronix HEI III module with an integrated RPM limiter (factory set at 5,500 RPM)? Seems like a win-win, at least in theory. ($70)

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

@SlantSixDan - I'll be honest, I'm waiting for the recap of that cap/rotor post - that's a lot to sift through. All good, but I'm looking for the short story (e.g. go out and buy this part #). Dist is all set :)
TY.

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

If the goal is optimal reliability and performance, maybe stick to stuff we know works well. The perfectly ordinary standard GM module is a whole lot better than any of the Mopar-style ignition boxes; no need to spend extra money. Also keep in mind a 5,500 RPM limit spec probably applies to 8-cylinder engines and translates to a 7,300 RPM limit on a 6-cylinder engine (useless except on an exotic 170).

As for the cap and rotor: if the advice were as simple as "buy this one and this one", I would have said that. The problem is you can't buy ones off the shelf any more that are good. You have to buy-and-modify.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

@DonPal and @SlantSixDan (anyone) - I could use some education on HEI coils, not my strength.

The coil Dan endorses (IC21) has a resistance of 1.5-ohms whereas a Pertronixc 45111 coil is at 0.600-ohms and is available in epoxy-fill similar to the e-coils (IC21 is oil filled). Wouldn't the Pertronix coil, therefore, be better suited for HEI conversion being discussed? Pertronix matches this coil with their HEI modules (along with other coil #s); so I'm guessing it's up to task for one of the modules noted in the writeup.

There are other epoxy canister coils in the 0.320-ohm range as well - what's the practical threshold for performance and durability in relation to resistance? Is that even an appropriate question?

This is not a racecar, just looking for max street-performance with longevity - it's a weekend cruiser, fuel mileage not important. It's a balancing act I know...

Thanks gents!
-Chris

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

The Pertronix epoxy coil will probably work fine.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.