MSD Failure

[frankym]

I have the blaster coil and new plugs and MSD wires (the 8.5 red ones). I am going to try to install the capacitor as MSD recommended in line with the 10 guage wire and also experiment with an additional fuseable link with a 7 amp fuse so that while I am continuing to trace the system, I don't have to wait 3 weeks to get another box. I will also use the rubber mounts to eliminate vibration. Most of these components are either bad or good. I have no intermittant problems with the system, it works until it melts down and doesn't work again. Many of the posts I read do talk about intermittant problems i.e. the system works, and then restarts after it cools down.

Here is the way it is connected:

Heavy red to the hot side of the starter solenoid
Heavy black to the engine block
Thin red to the ignition relay box (ign coil) which lights the tester when the key is on. However when I unplug the line to the relay, I can still light the tester with the red wire from the control box as I believe that red wire is spliced into the line that used to carry the ign coil terminal to the ballast resitor. The ballast resistor is shown on page 9 of the MSD instructions as ok to have in the line to prevent voltage from leaking through the control box. I suppose that I can replace that too or bypass it on the next try. Anyone think the ballast resitor could be doing it?

Orange and black to the ignition coil
Purple and green to the magnetic pickup in the distributor
blue to tachometer.
white: taped shut.

[frankym]

the relay I spoke of was my fan relay, which was providing the switched on power, although it does seem like that thin red wire from the control box ought to be linked to swiched power so that it doesn't have a live wire to it, although that should really make a difference. I have compiled a list of things to on my next box, if anyone can add to the list that would be helpful.

1. Run the spark test properly by jumping the purple and green wires with the center wire sitting next to a ground to isolate problem to control box only.
2. Install rubber vibration mounts
3. Install capacitor (MSD 8830 noise reducer) in line on the thick red power lead and ground it to the frame.
4. Install an in line fuseable link between the capacitor and the box with a 7-10 amp fuse.
5. Bypass the ballast resistor.
6. Reposition coil so that it is harnessed in the middle.

[Leroy]

I've had msd boxes in all of my cars, with great results. A little secrect is to buy used msd boxes at auto swap meets for 10-20 dollars and just sent them in to msd for repair. They have never charged me more than 20.00 dollars, so your total cost is $40.00
tops. They also update the boxes along with the repair, so check out those swap meets. Also if their are any circle track swap meets in your area, go to them a great place for fittings, brake parts, suspension parts, coil-over springs, stainless lines and fittings. These fellows general sell their stuff cheap!!!! They are always between Nov.thur Jan every year.

[Jack Zupan]

Well I guess I can add my MSD experience now. I put in a 6AL, Blaster 2 coil and MSD distributor in my Cobra this weekend to replace my dual point system. The car wouldn't start and in fact my timing light wouldn't flash so I was pretty sure it was ignition. After doing a lot of diagnostics I figured the box must be dead. I called MSD and they agreed. I have a new box coming from Summit so we will see how it does. But I am disappointed and I have a lot of work in the car now.

Jack Z

[frankym]

Well, I think I found my problem, and I will implement the fix this weekend, but before I disclose it, just a couple of points, and let me preface all of this by saying I like the theory of MSD and experienced great performance with it while it was working, so all MSD fans out there please don't get defensive and respond with stories of 100k miles without a glitch, I am sure there are many out there that have had 1000s of trouble free miles with their MSD systems.

I have a dear friend who has been building race cars for 30 years. He was out of contact until now but he said that for street use, I shouldn't waste my money on an MSD system, he said if I want electronic ignition go to a Ford HEI set up. He strongly reccommends a dual point system, namely because when the MSD "****s out" you need a tow truck, and with points, he can always get it going on the side of the road. He said the blaster coils do NOT like heat and street use produces A LOT of heat. He said that they used to use the MSD 8AL (didn't know they made that unit) and they would stock the car with 5 units because they have lost races in the final lap on account of a box blowing out. What many of the advocates of MSD on this board need to consider is how frequently they drive their cobras. If you drive it 200 miles per year, and there are many that do less, you really cannot speak to the reliability of the system. My friend said that at the end of each racing season, all the MSD boxes went back to Texas good or bad for an overhaul. (that makes sense now that the MSD tech said the turnaround time is 10 - 15 working days because it is race season). Voltage spikes are common and the fact that the control box doesn't have a capacitor built in is just frustrating, SO buy the MSD PN 8830 capacitor (they call it a noise filter). Also the fact that they don't put fueable links on the circuits that most frequently go bad, is a little crazy. The way he described it to me is that the battery is capabable of producing 13.9 volts, the MSD box likes something like 10-12, and when you have an electric fan switching on and then off, there is a surge on top. The capacitor will hopefully help a lot and I also need to find a better swithed power source. A sincere thanks goes to Rick Parker on this board who helped me figure that out early on and that hopefully will be responsible for the majority of the problem.
If I have misstated some of the details of his account, I apologize, but the crux of what he says is gospal in my book and any error is my own ignorance in retelling his logic.

The upshot of all this is that MSD stands behind their product 100%, but guess what, I don't really care about that when I am sitting with a dead cobra for 3 weeks waiting for the safe return of another box, especially after I had to get a tow back home from the last time it crapped out! Thanks to all the thoughtful postings from people, I genuinely appreciate this board, if my story suggests solutions to others, then I hope I can help others as they have clearly helped me!

frankym

also, try the rubber shock mounts and make sure that the thin red gets a good source of switched power. The capacitor get hooked in line with the thick red power wire and I am also putting a fueable link in line between the capacitor and the box, just thought might provide another layer of insurance, but probably won't deter a spike as it likely is a surge of only 5 volts that is blowing out the resistors.

[frankym]

Why The Capacitor is Needed

http://students.fct.unl.pt/users/ejr/ignite.html

Those same principles of inductance create a kind of paradox, because when you stop feeding juice to the coil, that is, when the points open and the magnetic field collapses, inducing the 30,000 volt current in the secondary, it also induces a current in the primary as well! It's not very much because there are only a few windings in the primary, but it's enough to jump a small air-gap, such as the one between the just-opening points in the distributor. That tiny spark is enough to erode metal away from the points and if there is any oily vapor inside the distributor, any oil on the points will become carburized; you'll 'burn' the points.

To keep your points from burning as they open and close, you'll need to provide something to absorb that spike of counter-current, something more attractive, electrically speaking, than the air-gap between the points. That's a job for a capacitor. To the counter-current, the capacitor looks like a black hole, an attractive one. The spike of current dives right in. And the points don't burn.

The points have a tough job, switching up to eight amps of current many times per second at highway speed. Indeed, as engine speed increases the efficiency of your ignition system decreases, thanks to heating problems and fundamental electrical laws. This declining efficiency has a serious effect on your spark voltage and results in poor high-speed performance, incomplete combustion and a host of other ills.

[Jack Zupan]

Just to finish up my MSD story. I got my new box in yesterday and decided to hook it up using my dual point distributor first before I went through all the hassle of last weekend with the new distributor too. After the installation, it was same as before, no spark. I rechecked everything with the voltmeter and found 8V to the switched wire at the ground I had used which was a windshield bolt. It read 12V at other ground points. I extended the ground wire to go to another point and the car started right up. So I had the box set to a poor ground. This was probably true for the first box also, although I'm sure I checked it at the time. It would be too much of a coincidence if that were not the case. So bottom line it was not MSD, it was my installation.

[jwoodard]

Jack,

Glad you found the problem and were able to cure it. Items like this can be very frustrating and getting good grounds on these cars can be troublesome. Everytime I've had any issues related to electrical with my car, checking for a good ground is always the first item on my list.

Jim

[Rick Parker]

Glad to see you found the problem! Many people had very good ideas glad I could help. As many of us will probably agree especially when you can't "SEE" what the problem is such as with electrical gremlins that plague us from time to time it is frustrating
and time consuming to attempt to troubleshoot the problem. We often will find that it is a very simple element that is being overlooked or taken for granted one that we HAVEN'T checked.
I'm glad it has turned out to be something so simple. FRANK : Before you step back to a point type distributor give this a thought Ford Motor Co as well as all other manufacturers steped up to electronically triggered ignition in an attempt to comply with ever toughening emission compliance requirements. The first Ford modules (in 1975) had a a horrible reliability problem. The problrem was ultimatly traced to the insulation on the windings within the coil pickup itself. Heat was causing the insulation on the fine copper wire to melt causing a short circut and a change in the voltage created by the pickup coil that was insuficient to trigger the Ford ignition module. Hence no secondary voltage or spark at the plugs. Numerous cars and trucks coming into the
shop "ON THE HOOK", and angry customers. However shortly the problem was solved and the Electronic Ignition has become standard equipment on all motor vehicles. (Bikes?) It has all but eliminated the changes in ignition timing that occur when the rubbing block wears in a point type distributor. Emission
compliance for the most part is the farthest thing from most of our minds, but we can benifit from the fact that with a modern electronic ignition system and high quality distributor with electronic internals we can have "ROCK STEADY" ignition timing that in "OUR" (read high performance) application will be nearly trouble free, with little or no routine maintainance thereby allowing us to focus our efforts in other directions.
That's all
Rick
See you all at Sears Point Mini Nats Sept 1 & 2

[frankym]

after doing all the things I outlined before, including grounding at the frame instead of the engine block (and making sure there was no paint at the ground connection point) the 4th MSD box wouldn't start the car! I tried the ground to the engine as before, and nothing. I didn't have time to screw around with reinstalling the points distributor so I am having my mechanic tow the car back in a week to have him try to troubleshoot the system with the 3rd box that MSD is returning (the first and only one MSD has seen and returned). Regardless of installation procedures, the box is way more sensitive than it should be. I have found the MSD techs to be less helpful than I would have liked, they couldn't tell me much in the way of the dianosis except that something (other than the MSD components) is cooking the main resistors and other electrical guts. Not much else in the way of suggesting how the bonfire is being caused except that I should recheck the installation and the rest of the electrical system. Surely something is being overlooked but for the box to not even start the car would mean that if the box wasn't defective then I would have had to have blown it out upon cranking and the voltage is lower during cranking anyways, so not sure where the surge is coming from and when. Recall that the other 2 boxes (Boxes 2 and 3) started the car and ran it for a couple of dozen miles before crapping out.

[Clark Creswell]

I'd like to install this unit in my car however this isn't very reassuring! What was the outcome (to date)? I used a Petronix unit in our FIA car and it's very reliable (street use), would consider doing same for the FE.

Clark

[frankym]

I am receiving the first box that MSD has looked at and repaired. It is supposed to arrive tomorrow and it will be reinstalled by the mechanic that installed it the first time. The box itself performs great when it is working, but they definitely need to build more protection within the box and provide some way of replacing fuses on commonly blown resistors by the car owner. If you do blow out a box, you have to reinstall your old ignition system and reset the timing etc before you get the box repaired 4 weeks later. still not a huge msd fan at this point. The technician couldn't tell me their diagnosis over the phone but he said it looked like there were defective parts. By defecitve it could just mean that the solder connections to the board were poorly done making it burn up prematurely, the burn in test remember is done on a bench, so it's like having a perfect sea to test the hull of a new boat. Throw in added heat, ancellary draws on electrical system, occasional jump start with another vehicle and wallah, reality. I have spent too much money and effort and downtime to really ever be positive about msd, but that could change after I am able to drive the car for the next 5 years regularly with the same ignition system and not have to rely on a tow service every other time i go out for a spin. This last box #4 would not start the car. #3 worked fine for 20 miles before it died, this last one was installed exactly the way msd suggested with a few additional safety measures.

[Clark Creswell]

Well that settles it! I'm sticking with the "Low Tech" approach and installing a Petronix System. Thanks for sharing your experience, hope you enjoy the rest of the season!