Anyone ever have an MSD (or other igntion box FTM) die a slow death

lendaddy · 07-07-2003, 12:44 PM

I guess the title says it all, by slow death I mean runs progressivly worse. I was wondering if this happens. I was running a Bosch blue coil with my MSD and apparently this is a big NO NO. I switched to a blaster coil but the damage may have been done already. So have you ever had one fail slowely and what were the symptoms? Thanks

john walker's workshop · 07-07-2003, 01:30 PM

the multiple spark should become a single spark at some RPM range. that doesn't happen sometimes and the engine craps out, backfires etc. no cure. MSD tech line guy said the 911 halls type distributors often don't relate well to the MSD system.

724doorE · 07-07-2003, 01:35 PM

Permacrap and recently my old bosch died a slow death. Missing and backfires got worse and worse till it was running on about three cylinders and not always the same three! Put on the msd and it was fine. Did you regap your plugs? The MSD seems to like big gaps like .050-.060 thousandths where as the bosch system requires small gaps like .025 thou. or so. might also help.

lendaddy · 07-07-2003, 02:07 PM

hmmm, Lots of info here . Thanks for the insight. I swear I can get two totally different opinions on anything! I bet can even find a defender of motor meister! I trust JW however and now I am confused again!

TimT · 07-07-2003, 02:34 PM

I have a 914-6 with a 3.2 for power.

The ignition is an SC dist triggering a MSD 6AL with MSD Blaster coil. It works great.

Ive only owned the car for a few months , but I know the p/o and he had no ignition issues.

Steve W · Steve W's Garage

I ran with a MSD 6A on a SAAB 900 Turbo with its Bosch LH injection and a MSD Blaster coil tapping its signal off the Bosch ignition module. It eventually died a slow death, with a progressively worse and worse ignition spark, evidenced with severe missing under boost. It took a couple of months and just died. All in all it probably lasted about 3 or 4 years. I hear a lot of them die unexpected deaths. I removed it finally and just used the stock Bosch system instead, which worked fine. The MSD is great for firing unusually lean or funky air/fuel mixtures, which would typically give a stock Bosch system problems. In my SAAB, when it was working, it was able to fire an excessively lean mixture without missing, and also under 30 lbs of boost pressure mixed with equal amounts of methanol/water injected with the gasoline.

Halm · 07-08-2003, 03:58 AM

When I bought my car last year, Otto went over it to make sure it could make the drive from CA to NC. First thing he did was remove the MSD. He said it was too unreliable.

724doorE · 07-08-2003, 05:57 AM

Hey Len, I was NOT disagreeing with JW! Was just telling my experience. They all die on someone some time or we would never need to replace anything. With electronics you can't really see any physical damage with the component until it is dead, but you may get indicators of dieing like poor performance. JW is correct about the mutiple spark thing, if I remember reading about this correctly, somewhere in the 3000-3500RPM range the MSD switches from multiple spark to single spark per pulse. If the trigger for that seqeunce goes bad, you get the multiple sparks all the time and a t high rpms that is a rediculous number of sparks per second causing problems. One reason they(MSD) are common is the fact that they are realatively cheap compared to the Bosch and permajunk (BTW I don't think John likes Permajunk either). I also belive the bosch ignition can be rebuilt( anyone verify this). If you are out in BFE and your ig dies you can go to any parts house and buy an MSD usually. Of course, if you have a spare bosch your golden as well.

I will say this,in all the magazine tests I've ever read on ignitions, the MSD was always the best, this was always in hotrod or rod and custom not P-cars. These electronics seem to have problems when incompatable system components are unknowingly used together. Easy to do considering the variety of choices on the market.

Another point that might be important here is the fact ( I think) that the MSD literature strongly suggests installing the MSD in a realatively cool place such as in the passenger compartment or in front of the radiator (AM car) and with the P-car we stick them back by that frickin hot engine with no air flow for cooling. Is that a contributing factor?

Where were all the CDI's mounted in the P-racecars? Why?

lendaddy · 07-08-2003, 06:13 AM

Dennis,

I was not referring to you. I appreciate your input! I was just sayinf that I got alot of good input on the MSD before I bought it and now some not so good input. I did not intend to offend you. I am picking up an new 6AL today and if thats not the problem I will have a spare right! Thanks again,.

724doorE · 07-08-2003, 06:25 AM

Cool, I didn't mean to be harsh, just don't want to be associated with any notion of opposing JW! Anyway, I think it is very important you use the correct coil for the msd. I think the 914 guys may kow something about MSD's and bosch blue coils. I think that is a bad idea, but I ain't that guru!
Well, Good luck Len, and hope to see that giant down at Thrown Hammers car benifit show!

Superman · 07-08-2003, 07:22 AM

I've heard plenty of folks lambaste Permatune, and glorify MSD. That seems to have been the conventional wisdom. But I went against that conventional wisdom when I replaced my CD box with a Permatune unit. The reason? JW seemed confident that MSD is not as reliable for our cars. I now use the Permatune unit with a Bosch Blue coil.

Also, I STRONGLY recommend that you isolate the cause before purchasing parts. I am happy to have a new CD unit as a spare, but as it turns out, my old one is still fine. The problem turned out to be a broken angel-hair wire in the "Hall" sender in the distributor.

john walker's workshop · 07-08-2003, 07:38 AM

don't worry about "opposing" me, i'm just one opinion on the board, and certainly haven't seen everything. i do in fact use a lot of permatunes, along with the recommended ignition coil, (the bosch blue coil), and really have had only one die over the last 10 years or so. bad grounds, bizerk charging systems, and wrong coils are the permatune killers. if the stock bosch unit was affordable, that would be the first choice, but customers tend to have a heart attack upon pricing one, and permatune is the logical next choice.

724doorE · 07-08-2003, 07:59 AM

I think you may have just learnt me why I have had bad luck with the perm's

I should know , but I ask you to learn me some more, tell me about this "hall" wire in the distibutor, is this the little pigtale that goes from the points to trigger the ignition and my tach or is there something else in there I am missing, remember I have MFI and an early car, no cis. I ask as I am curious about what the msd tech guy said. I could see on a later car with electronics there might be some natural incompatability with the MSD, but I'm curious as to what if anything in an early distributor could cause problems. Thanks, JW

rfng · 07-08-2003, 02:19 PM

Unlike the stock Bosch unit or the Prematune units, Msd's don't deal well with the heat in the engine compartment. They need to be install inside the car away from the heat for longevity.