MSD failure?

[olie05]

A friend of mine, whose car I work on occaisionally uses an MSD box. Recently one of the battery leads was disconnected while the engine was running in an attempt to shut down the engine. Reason for this was that there was no coolant in the engine and he did not realise it at first.

 

When the engine was filled with coolant, and everything was connected again, the car would not start.

 

MSD 6a was replaced with a new one and now the car starts just fine.

 

Also, the car is running on Megasquirt, with megasquirt triggering the MSD and the MSD firing the coil.

 

Now we want to figure out what happened to the crapped out MSD6A.

 

Can MSD boxes only be disconnected first from the "small" red wire, and then from the heavy red or black wires? I wish to understand why this failure occured. is this something typical of capacitive discharge ignition systems, or specific to MSD's?

[BRAAP]

Olie,

I really hate to say this. MSD has great products, “when it works”.

The fact of the matter is that the MSD ignition components have a failure rate that is, in my opinion, unacceptable. How many write ups here on HybridZ and elsewhere have you read regarding an MSD failure? We’ve seen it watching a PINKS episode where someone had an MSD box failure mid race. As much as I hate to say it, it is for the reliability reason that we will not carry or endorse MSD products. If MSD was to make an effort to get their failure rates lower than they currently are, we would be more than glad to personally run and endorse their products as they DO work. We prefer to use ignition parts that we can trust, not constantly be second guessing.

There is no debate whether MSD ignition components are up the task of igniting some of the most demanding and grueling combustion chambers out there. The debate is how long they will last! If we all knew what the “ideal conditions” we need to meet to keep the MSD boxes alive for an acceptable period of time, then we would sell MSD with the FIX kit to keep it alive. Till then, it’s J&S, Mallory, (Jacobs USED to be on our good list till they sold out and are now made across the border, Quality assurance has gone to CRAP ever since).

 

Good luck,

Paul

 

 

Paul Ruschman

[Michael]

Paul [and everyone] -

 

What is currently your personal favorite combination of distributor, capacitive-discharge multi-spark ignition box, and rev limiter? (MSD, Accel, Mallory, Crane, Jacobs, Pertronix, or “house” brands such as Summit, or something else?) This would be for a traditional carbureted V8 (in my case, big block Chevy).

 

Would you recommend a conventional distributor with vacuum and adjustable mechanical advance, or an nonadjustable distributor with “digital” spark control unit? I’m looking for reliability, convenience, adjustability and value - in that order.

 

What in particular do you think of the Summit clone of the MSD distributor:

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D850055&N=700+4294925143+4294839065+4294881256+400304+115&autoview=sku

 

… and the Crane 6000-6400 spark control unit:

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=CRN%2D6000%2D6400&N=700+4294925143+4294839065+4294925127+115&autoview=sku

[Guest Mike]

I bought Crane due to the caveats expressed by MSD owners. I hear fewer complaints about Crane failures than MSD.

[Sparky]

I bought Crane due to the caveats expressed by MSD owners. I hear fewer complaints about Crane failures than MSD.

 

That could be due to the fact that more people buy MSD than Crane, therefore when the units fail we are more likely to hear about it.

 

With that said, i've run a Crane box on my old Valiant and had good luck with it. My friend who races BMWs runs MSD boxes, the go through at least 3 a season. unreal, and totally unacceptable. at the last vintage race I was at I noticed several cars running two boxes, one live one, and one backup on a switch. I couldn't believe that people don't just switch brands, instead they just buy more of the same crappy product and hope that both don't fail.

[RTz]

Hilarious!

[JMortensen]

I've had an MSD 6AL on my car for 6 seasons of autox and 40K miles total driving. Bunch of track days in there too. The only time I had trouble was when I took it off to try to read the spark plugs (carb tuning--BTW O2 sensor is a much better idea than reading plugs) and when I reinstalled it I hooked the wiring up wrong. I sent it to MSD, they checked it, it was fine, so they sent it back with a manual and told me to hook it up correctly. I reinstalled it the right way and it worked fine. I know they have a rep, but mines been good to me. A friend with a 510 that was barely making over 110 hp showed an 11 whp difference on the dyno with the MSD vs with stock Nissan EI from a later model car.

 

If I were doing ignition mods again I'd probably go for the coil packs and a crank trigger just for accuracy's sake.

 

I've heard that pulling a battery cable to kill a car is a bad idea, so I don't know if I would fault the MSD so much in this case as the method used for stopping the engine. Could have just pulled the coil plug or put a hand over the intake.

[dr_hunt]

I've had problems with the MSD's, but they work when they work. I don't drive many miles on them either, so that's probably a big plus.

[Dtsnlvrs]

I've had an MSD 6AL on my car for 6 seasons of autox and 40K miles total driving. Bunch of track days in there too. The only time I had trouble was when I took it off to try to read the spark plugs (carb tuning--BTW O2 sensor is a much better idea than reading plugs) and when I reinstalled it I hooked the wiring up wrong. I sent it to MSD, they checked it, it was fine, so they sent it back with a manual and told me to hook it up correctly. I reinstalled it the right way and it worked fine. I know they have a rep, but mines been good to me. A friend with a 510 that was barely making over 110 hp showed an 11 whp difference on the dyno with the MSD vs with stock Nissan EI from a later model car.

 

If I were doing ignition mods again I'd probably go for the coil packs and a crank trigger just for accuracy's sake.

 

I've heard that pulling a battery cable to kill a car is a bad idea, so I don't know if I would fault the MSD so much in this case as the method used for stopping the engine. Could have just pulled the coil plug or put a hand over the intake.

 

 

I agree with you. I have had my MSD installed for about 6yrs now and have had no problems with it. Then again, I mounted it inside the cabin and out of the elements, and I do not do silly things like remove the battery cable when it is running I think the biggest thing that kills MSD boxes, and any black box for that matter, is a combination of heat, moisture, and vibration. If you mount the box in the engine bay, you are asking for trouble. Also you must use a suppresion wire...not the wires that MSD sells, but a tru EMI suppresion wire like Magnecor, even OEM style NGK work better at EMI supression than some other brands. Just my .02...maybe I have been lucky or maybe I found the secret...I do not know, just know it works for me.

[Dtsnlvrs]

Here is a picture of the mounting location for my MSD

 

[Guest Mike]

Many electrical component failures are caused by voltage dropping below tolerance. When voltage drops, current rises. This causes components to overheat and burn up. So... perhaps the issue is related to weak electrical systems. This is solved with bigger better batteries, higher current alternators, slightly oversized wiring, etc. Maybe adding a large capacitor directly to the power input of the MSD unit would help?

[z bomb]

Ummmm YEAH

Our shop keeps "known working" msd components (6AL, Dizzys) just to make sure the new components we get work. Two were bad in the last 6 months.

[datsunlover]

Well, I bought a 6AL box used last year for $100, and run a 280zx dizzy with out the nissan 'little black box' on it. Worked fine for a while, but the last few times I had it out, it'd start missing at higher RPM's. Engine was barely broke in, carbs were in good tune, ect.ect. Thing is, I have the MSD mounted in front of the passenger strut towwer and I think the heat and elements have taken a toll on it.. still, you'd think a unit like this would be designed to survive in that type of environment..

[JMortensen]

Are you sure that the MSD is the problem there DL? That could also be a loose connection somewhere. I had my MSD in basically the same location and never had any trouble. You could always send it back to MSD if you're not sure, they'll test it for free and fix it relatively cheaply if it needs fixing...

[datsunlover]

Well, I'm not 100% sure, but it seams to be a good bet.. it's not all over the place, it misses EVERY time I'm running flat out and get past about 5krpm. Actually, it feels like the rev limiter is clicking in prematurly (I have a 6000 rpm pill in it) to tell you the truth. Seams to be an electronic problem, as it's not every once in a while, it's consistant. I may never know, and it might not matter anyway if I manage to stick the 454 in there, and run the GM ignition/ect.

[Pop N Wood]

Recently one of the battery leads was disconnected while the engine was running in an attempt to shut down the engine.

 

Disconnecting the battery won't stop a running engine. Not until the disconnected battery cable touches metal and shorts out the electrical system. At which point it will cause a voltage surge possibly frying all kinds of electrical stuff.

 

I know all of this first hand.

 

Let's just say if you ever go hiking in the back country, make absolutely certain your headlights are off when you park. Especially when the trail head is 40 miles from anything. Otherwise you may have to temporarily borrow a battery from another vehicle.

[Guest Mike]

If it's missing at mid/high RPMs, it's possible that your voltage is dropping at the ignition box. If that's happening, you may burn up the unit. It may be something as simple as running bigger wires to the unit through a better electrical path or just replacing a defective or undersized battery.

 

Well, I'm not 100% sure, but it seams to be a good bet.. it's not all over the place, it misses EVERY time I'm running flat out and get past about 5krpm. Actually, it feels like the rev limiter is clicking in prematurly (I have a 6000 rpm pill in it) to tell you the truth. Seams to be an electronic problem, as it's not every once in a while, it's consistant. I may never know, and it might not matter anyway if I manage to stick the 454 in there, and run the GM ignition/ect.