Mopar electronic ignition box failure?

[340_GTS]

I've had the Mopar electronic ignition conversion on my '69 Dart 340 for about 5 years. Orange box. All of a sudden tonight at anything over 2000 rpm the motor was missisng and backfiring. The tach needle was jumping around like crazy too. So I immediately thought it had to be ignition related. After checking for obvious loose wires, plug wires, etc... I was at wit's end. So then I remembered having a really old orange box someplace. Found it, swapped it in, and the car now runs great again. Is this type of failure typical and do they only last 5 years and less than 5000 miles? Any other ideas?

[JVMopar]

I'm personally not a fan of the orange box. Even parts store ecm's last longer than that. I'm still using some junk yard OEM ecm's on my vehicles.

[primal]

the *orange* box is actually a slightly better performer the problem with the ones in last 6 yrs or so is they put this crappy transister in there. They can be rebuilt with a better transistor .. however there is alot in scrap yards too.

contrary to popular opinion slant six, small block, big block its the exacty same box and components. I have taken them apart (i rebuild snowmobile cdi units) and its the same not even a different board or component numbers.

[cudabob496]

my 440 kept quitting. Turned out the orange box was too close to the headers.

[340_GTS]

Someone said the chrome box was more robust. But Mopar does not recommend it for "street" use. What's up with that?

[peg leg]

Is the culprit on the cheapo boxes.
AS for the chrome box, I put one in the Demon to replace the FBO box that wouldn't work in heat. No problem since, and I have no idea why they don't recommend street use. Works like a champ,regardless of temp.

[Mopar Trac]

Mopar Tech Line years ago said that extended idle time on a chrome box will burn up the pick up in the distribitor.
That was his story anyway!

[rampage_82]

Originally Posted by Mopar Trac

Mopar Tech Line years ago said that extended idle time on a chrome box will burn up the pick up in the distribitor.
That was his story anyway!

Yeah sure, he was just making up what he didn't know.. All the pickup in the distributor does is just trigger the box, it doesn't handle any of the current like Points setup does... Well strike that as a matter of fact you can set up points to be used as a trigger as well, which makes them last virtually forever....

[340_GTS]

Let me ask you this: Do you think NAPA or some other brand may be of higher quality than the Mopar stuff they are making now? Or is it all made in some 3rd world country with junky parts now?

[JVMopar]

Got a Napa one in a W350. Has been in there for 6 years, but it doesn't see alot of miles. I wouldn't hesitate to by a Napa one. They are usually Standard parts that are known for good quality.

[dodger1]

AFAIK, the main difference between blue(stock), orange, and chrome boxes is the amount of dwell built into them - otherwise they contain the same components. I never could figure out why a chrome box could be detrimental to a streetable ignition system. I did run an orange box when I originally built the 360 (replaced the stock ESC) and didn't have any problems with it. I did have problems with the pickup module in the (reman) dist., and eventually went with the el cheapo Mallory 6 copy of an MSD CD ignition. That was 10 years ago. No ignition issues ever since. No ballast resistor, either, just an Excel SS yellow 12V coil to replace the stock lower voltage one.
As for primal's comments - come on, man - you don't "rebuild" these things!! Have you ever looked at one?? The guts are encased in a soft epoxy material and there's no "user-serviceable" stuff in there. Like I said in another thread - get your facts right before posting in this tech forum.

[cudabob496]

See below comment on orange box:

Tech Question
Erik Bakko, Brooklyn, NY, 72 Dodge Swinger 318ci

Dear Mr. Mopar Guru,

My ballast resistors have an expected life span of 3 months in my Dart. I put 4000 miles on the clock in the last year. I'm not sure what this little gem does exactly, I just know that it protects other ignition circuits and I'm shot down without it.

Standard Ignition Products rate theirs as "universal". I've burned out two of those.

Mopar Performance has three different models (0.25, 1.0 and 1.4 ohm) Haven't tried these.

I just found my new Mallory cracked in the middle yesterday. Super glue, zip ties and positive thinking are keeping me up and running. This was supposed to be rated for 0.75 - 1.5 ohms and offer variable resistance. Seemed substantial enough but it may have cracked last weekend when I drove in a downpour on the highway for 5 hours. I'll ask about phantom dash leaks another time.

The car has a fresh'nd 318 with a new Mopar orange ignition box, 50 amp alternator, stock distributor, new Mopar voltage regulator, MSD Blaster 2 coil, new Moroso wires and Accel plugs. Other than that, nothing much is different than stock with the ignition. It starts and runs beautifully.

Please offer any thoughts you may have and what I might do to avoid having to waste my time thinking about this little piece of pottery. I just want to know what it does and get one (and a spare) that works.

Erik, first, I need to know what the battery voltage is at 2,000 - 2,500 RPM. If it is much over, say, 14.2 - 14.5 volts, that's part of the equation Offhand, the Blaster 2 coil, which, I belive, is designed for C-D or MSD ignitions systems, probably draws too much current when used in a simple switch-type electronic ignition (such as yours). Swapping to a stock coil and stock ballast would be the easy fix.

Otherwise, you're probably exceeding the 20 or 25 watts dissipation most ballast resistors are likely rated at. The only fix at that point would be two fairly high resistance ones (>1.25O ) paralleled or 2 low- resistance ones (approx 0.5O) in series -- either would do the trick. But, with the Blaster coil, the "Orange Box" is almost certainly handling more current than it is designed for and is next in line to take a bullet.

There's only one other thing I can think of: Possibly you have some wiring error so that the ignition-run circuit (the ballasted one) is also feeding something else; therefore, too much current would be flowing through the balllast. The test: disconnect the ballast and be sure no other circuits have stopped working.

Rick

[cudabob496]

Looks like ballast resistor selection can affect orange box life:


Tech Question
Steve Whelan, High Wycombe, Australia, 1973 Dodge Challenger 440

HI Rick,
you must be sick of ECU/Ignition conversion questions so I found out most of the info I was looking for from your previous tech Q's as well as links from your website. But I can't find anywhere that tells me the correct value of ballast resistor to use for the Orange ECU upgrade from the stock black ECU. I learnt that the 5-pin black ECU needs a dual ballast (5 ohm and 0.5 ohm) and that the new Orange 4 pin ECU only requires a single ballast =- But what value?? Parts suppliers say a 1 ohm, but they supplied me with a 1.25. I have a collection here ranging from (as measured on my ohmeter) 0.6 to 1.6 ohms. What is the correct value to use and how critical is it to the operation? And another thing I can't work out is why they don't use pin 3 on the ECU any more? I guess they must have an internal resistor to drop the voltage for the unit? I am also doing the upgrade on my other vehicle -- an Australian '73 Valiant Charger 340. Thanks for any help for this simple question, and also thanks for an informative and sharp publication.

Steve-

The dual ballast's 5 ohm side wasm't needed on 4-pin ECUs, which began in the late '70's, since the ECU's internal circuitry was completely modernized, rendering it unnecessary and superfluous.

The ballast's value is pretty much an inverse curve: as the resistance decreases, the spark out goes up ("hotter" spark), RPM range also goes up, and emissions and low-RPM misfire go down. Sounds like a no-brainer, right? Well, there's no free lunch, mate! As the resistance goes down, current draw (amperage) goes up, and so does power dissipation, which is what makes all those good things happen. But more dissipation = higher operating temps = reduced reliability. That's why the "Gold" box has an extra heat radiator on the switching transistor.

Now that the engineering lesson is over, a direct answer: around 1.0 ohm seems to be a good compromise. Anything less, for long-term street use, either toss spare parts in the glove box, or add an extra heat radiator (it's a TO-3 power transistor, see sources such as www.digi-key.com or Radio Shack, etc.)

Rick

[fat 360]

I had a chrome box going on two different cars,both daily drivers,for ten years,no drama's!

[peg leg]

The ballast resistor reduces the current through the primary of the coil in the run position of the ignition key. In the start position, it is out of the circuit, to give the coil full current for higher secondary voltage to fire the spark plugs. It burns out because it is used any time the engine runs, which is most of the time.
By the way, I have never lost a ballast in my life.
The difference in resistance determines the coil primary violtage value. Higher resistance, lower secondary voltage.