Electronic points module failure...again

[Delbert]

I have an Accel electronic points eliminator kit. (PN #2020) Over the last year and less than 100 miles I have gone through 3 of them. The most recent lasted less than 10 miles. I have no idea on where to start looking for the cause. I have the proper coil and plug wire set that is required/suggested by Accel.

The only thing I have done different since going from the Mallory unit to the Accel is I eliminated the ballast/resistor I was told by an Accel tech that it's not used with my coil (#8140 superstock) and wire set, and is clearly stated in the instructions.

Looking for any suggestions to what may be causing it to fail.

 

[Steve83]

You first need to identify the failure mode - what exactly went wrong? And how are you pinpointing the module as the problem? What tests are you performing? What readings are you getting? Pics/videos would help, and they're free & easy to embed in you posts:
http://www.supermotors.net/forums/thid-5972-how-do-i-post-pictures-sounds-and-or-videos

 

[Delbert]

You first need to identify the failure mode - what exactly went wrong? And how are you pinpointing the module as the problem? What tests are you performing? What readings are you getting? Pics/videos would help, and they're free & easy to embed in you posts:
http://www.supermotors.net/forums/thid-5972-how-do-i-post-pictures-sounds-and-or-videos

This is the fourth time this has happened 1 Mallory and 3 Accel units. (I believe Accel bought out Mallory) anyway The only reason I know it's the module is it will start and run after I replace it.....for a short time. I'm sure it has to be something else causing it to fail?'

2 weeks ago I gave up and took it to a shop. They discovered it was a bad module as I thought. They replaced it. I drove it home. 2 days later I started it in my drive way and ran it for about 20 minutes. 3 Days ago I drove it a few miles around the neighborhood and parked it. Everything was great. Tonight it wont start. Cranks but no explosions. Fuel going to carb and no spark to spark plugs. Frustrated I stopped there. I suppose this time it could be my coil or something but experience with this problem tells me it's the module again. I'll investigate further and get some pics in the morning but assuming it is the module, I'm wondering what could be causing it to repeatedly fail?

 

[Delbert]

Can I be blowing the module if the ignition is left on "ON" for too long? I notice these have all failed while I was starting the motor.
I use a remote starter switch to start the engine. When it's cold or has been sitting for long, do to carb issues starting it may take a little more time causing me to leave the key in the "ON" position for longer than usual. Sometimes I forget the key is even on. Could this be the cause of my repeated module failure?

 

[rmk57]

The early Petronix units would cook if you left the key on for to long. The newer ones are circuit protected against this from happening.

Cant speak for Accel/ Mallory, but you would think they would have the same technology built in.

I'd put a $15 set of points back in and change them every 4-5 years.

 

[DirtDonk]

If it's just taking a long time cranking waiting for it to start, that's "usually" not enough time or the right circumstances to fry an ignition module. You need to leave the key in RUN/ON for a few minutes just sitting there.

Not sure what the dynamic is that actually causes heat to build up in one condition and not in the other, but it's how points worked as well.
So how long is the key ON before you get to cranking? How long is it ON in between cranking?

And even though I'm all in favor of removing a ballast resistor when you can, you might try putting it back in to see if that helps.

What exact coil brand and part number did you buy?

Paul

 

[Delbert]

If it's just taking a long time cranking waiting for it to start, that's "usually" not enough time or the right circumstances to fry an ignition module. You need to leave the key in RUN/ON for a few minutes just sitting there.

Not sure what the dynamic is that actually causes heat to build up in one condition and not in the other, but it's how points worked as well.
So how long is the key ON before you get to cranking? How long is it ON in between cranking?

And even though I'm all in favor of removing a ballast resistor when you can, you might try putting it back in to see if that helps.

What exact coil brand and part number did you buy?

Paul

The coil is an Accel PN 8140. The module is an Accel PN 2020

Yesterday I suppose my ignition could have been on for as much as 4 minutes?

 

[markatherton]

failure

Do you have original wiring? If so, the voltage is reduced from the ignition to the module via a resistor wire which has the same effect as a ballast. Pertronix just started selling a kit to increase the voltage back to 12 volts because of the number of module failures they were haveing. If you have a centec aftermarket harness then "never mind"

 

[Delbert]

Do you have original wiring? If so, the voltage is reduced from the ignition to the module via a resistor wire which has the same effect as a ballast. Pertronix just started selling a kit to increase the voltage back to 12 volts because of the number of module failures they were haveing. If you have a centec aftermarket harness then "never mind"

Most of it is original however awhile back I ran a new wire from the ignition switch to the coil....I think that bypassed the resistor wire? Right now I'm getting 11.1V at the + side of coil. (on the -side I get 1.4).

 

[72Sport]

Not sure what you are using for a distributor but I had a stock rebuild in mine. The rebuilder left out the adjustable stop for the vacuum advance. I think the tune up man said I had 57 degrees total advance which caused the wiring to pull the out of the Pertronix module. The break in the wiring was not visible. Fortunately I live close to Pertronix and I was able to take the bad module to them for testing. The vacuum advance problem was found after I replaced the bad unit with a new one.

 

[englewoodcowboy]

Broncos didn't use a ballast resistor, they used a resistor wire if you still have a stock harness. The electronic modules need full clean 12vdc to operate. We have had to run a relay triggering it with the factory coil wire because relays do not need 12vdc for a trigger and then supplying 12v from the battery to the distributor and coil. No issues since that simple modification.


Sent from my iPad using Tapatalk

 

[Steve83]

Not sure what the dynamic is that actually causes heat to build up in one condition and not in the other...

Points are a mechanical switch that turns the coil on (closed) & off (open). If the engine happens to stop in a position that the points are closed, and then you leave the key in RUN, the coil will have continuous power, and it can cook. The difference is duty cycle (like a welding machine): when the engine is spinning, the coil is pulsed on for roughly 20% of the time (probably less), so it doesn't overheat; when the key is on with the points closed, the coil is on 100%, and it doesn't radiate heat fast enough to dissipate what the electricity is bringing in, so it cooks.

Electronic ignitions don't do that. They read the incoming pulse from the distributor (or some other pickup location) and logically control the coil power. If there is no pulse (regardless of engine position), then they don't turn on the coil, and the coil doesn't even get warm. So an electronic ignition can never cook a coil under any normal operating mode (including a key left on with the engine stopped for days). The module may cook ITSELF if the voltage is too low because it may try to draw too much current. But that should be VERY rare, even with a fault in the wiring. So I don't think that's what's happening here.

 

[ntsqd]

Under the Accel label it's all Mallory junk, which I view as a severe insult to Accel. MSD isn't much better.

Unless the engine is a race gas only kind of build I'd convert it to a Dura-Spark II system and drive it!

If it is a race gas only, non EFI kind of engine I'd look at Electromotive or M&W ignition systems.

 

[Delbert]

Under the Accel label it's all Mallory junk, which I view as a severe insult to Accel. MSD isn't much better.

Unless the engine is a race gas only kind of build I'd convert it to a Dura-Spark II system and drive it!

If it is a race gas only, non EFI kind of engine I'd look at Electromotive or M&W ignition systems.

That's funny I thought it was the other way around. My Mallory unilight module lasted over 10 yrs and I never had to touch it. Since then I've gone through 3 Accel modules. But I'm sure something else is causing them to fail other than the module itself.
I will look into the dura-spark II. Thank you. Question is, whatever is causing my problem still be a problem regardless what system I go with?

 

[ntsqd]

You've gone thru 3 "Accel" modules because it is Mallory product re-branded. What used to be real Accel product is no more.

If you convert to D-S II get all of the DS-II pieces and do a clean-sheet conversion. Use nothing from the current or an past systems. Only variance I know to work is to use an 'E' Core coil off of a later model.

 

[Delbert]

You've gone thru 3 "Accel" modules because it is Mallory product re-branded. What used to be real Accel product is no more.

If you convert to D-S II get all of the DS-II pieces and do a clean-sheet conversion. Use nothing from the current or an past systems. Only variance I know to work is to use an 'E' Core coil off of a later model.

Now I understand what you are saying about Mallory/Accel. Thanks for the clarification.
I was just reading another thread that you had commented on the Dura spark. You might of sold me on it. Would you mind explaining what you mean by "clean-sheet" conversion. What's all involved with the conversion? I have seen threads and talk of the dura-spark for years but never paid attention because my system was working fine.

 

[ntsqd]

Others have documented the D-S II conversion better than I can, so search the topic here and on the whole web. Shouldn't have any trouble finding wiring diagrams etc. If you want the start -retard function look into which starter solenoids will work. Not all do, some will hang the starter motor. Generally my advice is to find the most maintenance-deferred blue strain relief donor in a junk yard as it will be most likely to have original parts. The original parts work better than almost all of the aftermarket replacement parts. This is particularly true of the modules though p/ns for quality replacement modules have recently surfaced here.

Can convert your OEM points dist to DS-II configuration if you'd prefer. Can walk you thru that when the time comes as I've done several.

A note that may or may not help; the later straight 6 cars with DS-II have the longest module to distributor wiring loom that I've found. This can be helpful when the desired module mounting location is some distance from the dist. or you're trying to hide the wiring for appearances.

By clean sheet I mean don't use any of your existing ignition hardware or wires (excluding the high voltage stuff, that shouldn't matter). What I'm proposing is by doing the conversion with all new parts that you will likely eliminate whatever the problem is w/o having to go searching for it. This may not work, but it has a high probability of working.

 

[Delbert]

Others have documented the D-S II conversion better than I can, so search the topic here and on the whole web. Shouldn't have any trouble finding wiring diagrams etc. If you want the start -retard function look into which starter solenoids will work. Not all do, some will hang the starter motor. Generally my advice is to find the most maintenance-deferred blue strain relief donor in a junk yard as it will be most likely to have original parts. The original parts work better than almost all of the aftermarket replacement parts. This is particularly true of the modules though p/ns for quality replacement modules have recently surfaced here.

Can convert your OEM points dist to DS-II configuration if you'd prefer. Can walk you thru that when the time comes as I've done several.

A note that may or may not help; the later straight 6 cars with DS-II have the longest module to distributor wiring loom that I've found. This can be helpful when the desired module mounting location is some distance from the dist. or you're trying to hide the wiring for appearances.

By clean sheet I mean don't use any of your existing ignition hardware or wires (excluding the high voltage stuff, that shouldn't matter). What I'm proposing is by doing the conversion with all new parts that you will likely eliminate whatever the problem is w/o having to go searching for it. This may not work, but it has a high probability of working.

Great thank you! Been researching threads and I think that's the way to go. I guess the first thing to do is start gathering parts.

 

[Delbert]

Problem solved!

It was my tach this whole time! Thanks to Broncobowsher ;D who answered a question of mine on another thread. My tach attached to the neg side of coil was grounding. I removed it and all is well. I cant even begin to describe how F'n happy I am......Wooo Hooo!;D;D;D;D;D;D;D;D;D