Has anyone else experienced intermittent failures with a MSD 6AL-2? I had the motor apart over the winter for some head work. Since putting the motor back together I now have an intermittent ignition problem. After first firing the motor I spent a little time adjusting timing and carb. Once I thought it was in the right ballpark, I shut the engine off in order to disconnect the test equipment. To my surprise, the motor would not start back up.

I tinkered with the carb and timing to try to put it back to the earlier state when the engine first started but that didn't help. There was no problem with fuel.

After trying for a while I finally gave up, thinking that perhaps the battery was low after sitting all winter and the amount of cranking I had done. The following weekend, I tried again and the car started right up. The timing and carb were put back their best settings at the time, and I went for a drive. The drive lasted about 15 minutes, and as I was approaching my subdivision the engine suddenly died. I tried to restart it but I could tell from the sound that there was no fire in the holes.

After getting the car back to my house (interesting experience since I was 1/2 mile away when it died) I tried the MSD diagnostic of putting the coil wire close to ground and shorting across the green and purple trigger wires. There was no spark. At the time I thought this pointed to the box so I called MSD during the week. The MSD Tech said that if you don't short these wires in a periodic fashion like an actual ignition signal that the box will ignore the signal and not fire the coil. The Tech thought it was more likely a problem with my distributor (MoPerformance).

Friday night I pulled the distributor and gave it a good look over. The reluctor gap was a bit wider than 0.008 so I snugged it to 0.006. The pickup impedance was 328ohms. I have seen some posts which indicate this should be more like 500-600 but I have 2 other pickups that measured in the upper 200s, so for now I am considering that OK. I measured the AC voltage while spinning the distributor and could get anywhere from 0.7 to 1.1 depending on how fast it was moving.

Today I started the car and again set timing and carb after letting it warm up. After tinkering for 20-30 minutes the engine again just quit. I had tested my test technique with the trigger signal before firing the car and proved to myself that I could tap a shorting wire across the purple/green mag trigger wires and get a good series of sparks between coil wire and ground. Once the motor died, I tried this same thing and got nothing. This test bypasses the distributor so I feel that is ruled out as the problem.

To rule out the coil, I connected the battery positive via jumper directly to the + terminal of the coil (MSD Blaster SS), and jumped the - terminal of the coil to the battery negative. When I broke the connection to the negative, I would get a weak spark. This spark was much weaker then what the MSD generates, so I tried the same test with a second coil and observed the same weak spark results. Based on that I suspect the weak spark is due to the speed at which I can pull the jumper wire from the battery negative and is not indicative of a coil problem. I hadn't tried the coil test prior to initial fire but I will try that next time.

So I am again thinking the problem is the 6AL-2 box. Something makes it get into a state which it will not fire the coil. I don't know if it is temperature (the box is not hot to touch but the engine was up to operating temp and the ignition box is on the inner fender) or just operation time. I will be calling MSD again on Monday, but in the mean time, does anyone have suggestions on other tests I can try?

Last time I spoke to MSD the Tech said the boxes don't get intermittent; they either work or not. I am doubtful though. I have gone thru the wiring several times and everything is tight. The MSD red and black go direct to the battery and the MSD red run wire has 12V on it when there is no spark.

Thanks for the input.

Dave

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Last time I spoke to MSD the Tech said the boxes don't get intermittent; they either work or not.

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i can't believe anyone that has ever worked with electronics would make a statement like that. without going through a lengthy explanation of diagnostics which may or may not discover the problem usually the best way to start checking something like this is with a known good component. there is always the possibility that there is a wiring or similar problem that could damage the new component but it's normally worth the risk. if you put a known good box in it and the problem is solved you have your answer if not then further checking is required. having an ignition tester at hand is also helpful but intermittent problems are the worst.

Thanks for the thoughts. I wish I had another box I could swap in, but unfortunately I switched from a MP Chrome box to the 6AL-2 and made a bunch of wiring changes along the way. I could re-wire again and move back to the Chrome box but that is not an experiment with a single variable and I'm trying to avoid that.

I agree intermittent problems are a real pain. I'm going to call the MSD Tech line again during the week, and am just trying to gather as much info as I can prior to speaking with them. One thing I also checked was whether 12V was present to the coil when the ignition switch was on (motor not running) and the MSD was in control. I didn't know what to expect, but there was only about 0.04V. Any thoughts on this? It is my understanding that the MSD charges the coil in a unique way.

i had some intermittent hot starting problems with my msd6al. it turned out to be a bad pickup in the distributor.

I just went thru this exact same thing. I swapped coils, distributors. I checked and rechecked all grounds and power leads. Car would run anywhere from 10-20 minutes and die, after approx a ten minute cool down, it would repeat the cycle. I happen to have a spare 6al, put it in, no more problems! I need to send it back to MSD, not looking forward to arguing with them to get a return authorization. I am an electronics tech and anyone who would say electronics cannot develop intermittant problems have never worked with electronic devices! Good luck!

"i had some intermittent hot starting problems with my msd6al. it turned out to be a bad pickup in the distributor. "

I had considered this, and I believe this is what the MSD Tech was thinking. However, once the ignition was not working, I tried to trigger the MSD directly from the trigger wires (distributor is no longer in the system) and I was not getting any spark. When everything is cold, I can reliably get spark by shorting a wire across the green/purple wires in a periodic fashion (tap-tap-tap). In my first attempt at this test I was only sporadically shorting the wire, and apparently the MSD may ignore such a signal since it does not look like an ignition pulse. If anyone tries this remember to tap in a rapid, constant pulse.

If it comes down to me having to buy another box, I will likely replace the pickup first, just in case.

Lee,

Thanks for the experience. I have not figured out how long of a cycle time my problem has. Once the engine died yesterday, I tinkered on and off for probably an hour before I ran out of ideas of things to check, and the motor still would not fire. I'm sure if I go out today, it will fire up on the first crank.

I am also curious to see how they handle it. I suspect my unit is over 1 year old but not by much (need to see if I can find a receipt). If the answer is "sorry you are on your own" I am not going to be happy. Perhaps MSD can suggest some other diagnostic I can try....

Had the same problem several seasons ago, changed the box
and all is well, just had to replace it again this past
season, the msd boxes are not as good as they used to be,
imho, they don't stand up like they used to.

Don't send it back to msd, send it to Pat Collins at,

www.techwestracing.com

check out their web site, and give Pat a call, you won't
be sorry.

Dave

I had the same problem, I was using solid core plug wires, changed the plug wires to and its been fine.

"Don't send it back to msd, send it to Pat Collins"

Thanks for the tip. I will give him a call. It is good to know at least that others have seen this. It is frustrating though since even though the box is over 1 year old, it has very little run time on it.

"I had the same problem, I was using solid core plug wires, changed the plug wires to and its been fine."

I am running the MSD 8.5mm Super Conductors. I could see that solid cores could cause enough noise that if it couples into the trigger wires from the distributor could confuse the box. Even though I have the Super Conductors, which are not solid core, I did consider this, and made sure none of the spark plug wires were touching or very close to the green/purple trigger wires.

I plan on calling them anyway about an old 404BC box that used to run really well on my car then one day during warm up it just shut off.
Thanks for the tip on sending out my old one I think I will send them my spare 6AL along with my old 404 gold box.
Gus

Just wanted to provide an update on my saga....

I did speak with Pat Collins, and he seems like a knowledgeable guy. Very friendly and he spent some time on the phone with me, discussing my problem on his time. Definitely someone I would recommend if you have a need for ignition work...

Anyway, after talking with Pat I still had some uncertainty on whether my problem was the 6AL-2 or something else. I tried to re-create the problem again, and to my chagrin, the car ran fine for about 45 minutes, at which point I decided not to keep idling the car in the driveway. However I was still scared to take the car far from home in case it left me on the side of the road again. As an experiment, I decided to buy one of the MSD Streetfire units since it was pretty inexpensive, and plug compatible with the 6AL-2.

I swapped the Streetfire in a few weeks ago, and have been driving the car locally for a few weekends. Never had a problem and my suspicion on the 6AL-2 was escalating. That is, until last evening.

I did some work on the car during the day on Saturday, and decided to take the car out just prior to dinnertime. As I am driving along, I feel the ignition stop for just a second and then come back. All of the sudden I am hoping that I can the car home quickly. Unfortunately I get caught at a long light, and once it turns green I don't get very far before the ignition quits completely.

Luckily I was coming up on the local hospital and was able to roll the car into a mostly empty portion of the parking lot. I thought about checking with the folks in the ER to see if anyone could revive the patient, but decided they probably would not see the humor in that.


Anyway after having the wife come retrieve me and eating some dinner I returned to the car with tools and meters. Again I confirmed the 12V source to the box was getting voltage, and tried triggering a spark by tapping on the green/purple trigger lines connected to the distributor. No spark. After staring at the car for a bit, I remembered that there was a cable extending the trigger wires from the box. Going to the trigger inputs at the first connector, and re-trying the experiment....ah ha! Spark!!! My mood started improving immediately, as I traced back the trigger wires to the distributor. I could still get spark by jumping the connector at the end of the extension trigger wire which MSD provides. The only section left is where I mated the MSD trigger wires to the stock Chrysler wiring to the distributor.

So, it appears I only have myself to blame. I am going to look at it closer today, but it looks like two dumb mistakes on my part: I used crimp style butt splices (instead of soldering), and I reused the original Chrysler 2 wire molded connector. My tests last night indicated there is something intermittent in the molded connector...

Anyway just wanted to update this post since I had cast some doubt on the MSD box.

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I used crimp style butt splices (instead of soldering)

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soldering things is not necessarily the answer, i learned that the hard way. i made the mistake of soldering though i had been warned against it and it cost me a shot at defending a national title. i went from a magneto to a MSD, soldered and heat shrunk everything (teflon MIL spec wire). couple races into the season i start having intermittent loss of ignition during a run which aside from costing me the round would damage a $200 shift fork (drag bike trans). checked things time and again, gave up and decided to go back to the mag. while removing the MSD the last wire i went to remove on one of the coils came out of the heat shrink fractured at the teminal...which is what i was warned against by someone that works on very high end uninterruptible flywheel power supplies (like the ones used for cray computers). afaik aircraft wiring is crimped not soldered. solder can/will wick up the wire and with vibration can cause a fracture. the problem with crimping is people don't use the right quality connectors and crimping tools.

i was warned not to solder and thought i knew better...i was wrong

the factory recommended repair in AIR BAG wiring under the hood is DO NOT SODDER the connections. use heat sealing crimp connectors.

on any wire connection i make i use those connectors. they work great and are easy to work with.

That is interesting information. Unfortunately I am in the camp of "not having a good crimp tool" which I admit is certainly a contributing factor to my poor connections.

So if I understand you correctly, the concern with soldering is that the wire after the solder joint can crack? Do you understand the mechanism for that? It seems to me that the wire would be as strong as it ever was at the point beyond the joint.

It ends up that the problem was in the re-used molded 2 wire connector. Depending on which way I bent the wire in the pigtail, it would have connectivity or not.

Does anyone know a good source for the Chrysler 2 wire molded connector which mates with an electronic distributor?

"wiring under the hood is DO NOT SODDER the connections. use heat sealing crimp connectors."

Where do you purchase these sort of connectors? I have been using ones I purchased at ACE hardware, and combined with my cheap hand-help crimper, do not get the best of joints.

My coil failed a couple of weeks ago and I changed it and all was well till Saturday when the ignition quit again. I thought I had this fixed, but more and more I am suspecting the 6AL.

The only box I have as a spare right now is a Crane High 6...I am debating to swap them...I never liked the MSD6 anything, and if its shot, I will probably never buy another one of their products. It has been such a pain to narrow it down, I am even sure I could keep my composure talking with them.

"but more and more I am suspecting the 6AL."

That is exactly where I was, and I know how frustrating it can be. I spoke with MSD twice on the issue. I wasn't impressed with the first fellow but the second time the guy was OK. Pat Collins was really nice and helpful. After talking with him, I still wasn't sure the 6AL-2 was at fault.

At the time, I struggled with the decision to buy the Streetfire unit but in the end decided it wasn't too expensive, and it would give me a "plug compatible" backup in the future. Are the wiring connections for the Crane unit the same as the MSD?

I found the diagnostic where you tap a jumper between the trigger wires to be really helpful. This was the first thing I did last night, and as soon as I saw there was no spark with the Streetfire unit, I knew my 6AL-2 was probably fine and I had a different problem since it seems like a long shot that both MSD products had the same issue for me. This diagnostic removes the distributor from the system during the test. I had also taken a spare coil with me, and tried that also with a "no spark" result.

After making sure the MSD had 12V on the run line, I looked closer at the trigger wires as I mentioned above and found the basic issue. Today I proved it was the molded 2 wire connector.

Once I get a good connector back on the car, I will swap the 6AL-2 back in. If I ever get the car to a chassis dyno, I may even try a comparison test between the two.

I hope you can find your issue soon!

Your distributor connector that went bad is the same as a 2-wire trailer connector. I discovered this wiring my MSD6A to my Chrysler distributor. It costs about $3 and it works. It also allows me to keep my orange box on the firewall for a spare. I used a twisted pair for an extension, soldered the MSD connector on one end and the trailer plug on the other. The MSD box is mounted on the fenderwell.

R.

Thanks for the tip! I did look at the trailer connectors at my local Carquest and NAPA, and the ones I saw are actually a little smaller (not as wide). I did end up buying one at NAPA, and put it on the car, but the male end does not close the overlapping rubber portion (it just butts against the connector instead of slipping inside) so is likely not weatherproof. I also found something on Summit that I will get on my next order but it is not possible to judge the connector width to see if it is right.

There is likely some variation to what is on the market, and others might be able to find something that works at the local auto store.