MSD Distributor issues
 

Brand new, right-out-of the box MSD 8352 Pro-Billet "Ready to Run" distributor appears to not work. I'm not running an ignition box. Installed the unit, and then tried to fire the engine up.

Fires right up, then dies. I tried this several times, to make sure I was getting fuel.

Testing: I disconnected the distributor pigtail from the coil and measured the voltage at the + and - terminals on the coil: +12.44V. I install the distributor pigtail and the voltage at the coil terminals drops to +2.44V.

Since I have +12.44V at the coil terminals with the distributor disconnected, and it immediately pulls down to 2.44V when the distributor is connected I reason that the distributor has failed.

Am I missing something?

DD

Get this: My original 8352 failed, but it was several years old and I chalked it up wear. Since I am building a new engine and didn't want to spend much on my current engine, I replaced the failed distributor with a Summit Racing MSD knock-off for $190. THAT unit had an internal intermittent short, and I returned it. Frustrated, I dropped $365 on an 8352 that worked fine for two weeks, then failed and required me to flatbad the Cobra home. THEN, I get this unit as a warranty replacement (Summit Racing is pretty awesome in service) and it fails right out of the box. I'm pretty fried on all of this trouble-shooting. I just wanted one more season out of this engine before I drop in my 331 stroker (which, I regret to say, also has an MSD distributor that I installed...). This has been maddening! :JEKYLHYDE

Doug,

I've been there. Sorry to hear it. I finally took out the MSD dizzy and box and installed a Pertronix Flame Thrower III Dizzy and it was like night and day. BIG solid spark, self-contained (no box), and includes an internal rev-limiter. A nice polished billet piece. Got it with the black cap. I am done with MSD.:cool:

'Plug n Play' Billet Distributors

I got one from these guys:Distributors
Bought it at the local O'Reilly's, I want to say around 80 bucks ready to go, then bought the Summit brand ignition box.......
It's only been a month or two, but very happy with this set-up so far.........

BTW: I'm done with anything MSD, just too many problems!!!!!!!!!!!

David

Doug if its just a season you want to use it for, Napa, duraspark dizzy...about 60 bucks...it will work with the MSD box

This is a very common problem.

MSD pickups are unreliable.

I for one am satisfied with MSD products. They hate extreme heat but more so vibration.

Well, I was pretty happy with my MSD 8352. I ran it for about 5 years, and then it failed. I thought it was a bad coil, but traced it down to the distributor itself. But then, having had TWO new replacement MSD 8352's fail in ONE MONTH, plus a MSD knock-off fail as well, I've lost confidence in their products.

And when you lose confidence, there's no point. I don't enjoy happily driving along and having my engine suddenly die and fail to restart. And I don't want to drive my Cobra wondering at which moment it's going to fail.

The first failed 8352 I decided to replace the pickup, but this didn't revive it. There is a circuit board in the base of the distributor, and I'm convinced this is where these are failing. A simpler design would be more reliable.

DD

Doug,
You do have an "ignition box" on the 8352, it's buried in the base of the distributor. I'm not a fan of this old design as the electronics are exposed to high engine heat and vibration. A remote ignition box mounted outside the engine bay is more reliable, regardless of the brand. While its possible youve purchased a number of defective 8352s, I'd suspect something else is contributing to the problem. The 2.44 volt reading indicates the ignition module is working.

I thought that as well, but consider this:

Out of the total four failures:

The original unit may have failed due to alternator output issues I was having a few months back. That's been repaired and is no longer an issue.

The "Generic Brand" MSD 8352 knock-off failed due to an internal short within the distributor. The unit worked intermittently, based upon the position of the distributor pigtail. Move the pigtail while the engine was running and you could kill it. Move the pigtail when the engine was not running but the ignition on, and you could hear an audible 12V zap coming from inside the distributor.

The most recent MSD8352 was bad right out of the box. Plug it in, and the unit pulls the ignition voltage down from 12.44V to 2.44V.

I've lost confidence in MSD Distributors. I've gained confidence, though, in my ability to remove and install a distributor---I've lost count, but I think I've installed a distributor over ten times now. All in the last two months!

I'd rather be out (confidently) driving my Cobra!
DD

As a side note to the MSD dilema; given the general harshness of the ride in a Cobra it may be prudent to give the CIrcle Track and Road Race varients of the MSD boxes the nod instead of the others intended for "Street" cars.

Doug,
It's supposed to pull voltage down, that's what fires the coil

Vatdevil: I suggest you get your DMM out and go measure the voltage at the coil terminals on your SPF. Ignition on, engine not running. Please report back here.

DD

Zero volts.....capacitive discharge. Easiest way I know to test an inductive ignition like yours is to hook up a 12V LED...it will flash on /off if functioning properly. The old Mallory unilite I had would vary voltage from 12 to 2. If testing with engine off, I would get either 2 or 12 volts, depending where pickup was in its cycle.

I read 2.44V---always---regardless the position in timing, if I measure the voltage with the ignition on and the engine not running. I have also compared my test results to a good, working MSD 8352 which reads +12.54V on my system---always---the 0V pulses being so short in time that you'd need an oscilloscope rather than a DMM.

As I mentioned earlier, the engine starts briefly and then dies. When this happens the coil voltage goes UP to +12.44V, and then the engine dies when the voltage goes down to +2.44V.

Nevertheless, a good, working MSD 8352 would show +12.4V (or so) ignition on, engine running or not, with the pulses so short in time they would not be observable with a DMM.

DD

I thought some of the capacative discharge systems produce about 500volts at the coil?
After reading all your posts, I'm put of getting a MSD or any other box ignition. I really wonder how much more power it produces opposed to a simple electronic dizzy and Accel supercoil?
JD

Yes, CDI does have 500-550 volts at the coil, BUT the coil is used as a step-up transformer only. It does not saturate then collapse like inductive ignition does.

That 500 volts is also only about 20% of the discharge time (versus crank degrees) of some factory HEIs and some "decent" aftermarket electronic ignitions.

Factory HEI has "high voltage" at the coil negative terminal.

I have some mates with MSD, but I still have doubts about their products.

I don't know that the MSD products are "that" much better than others and even stock units........I've seen hundreds of road race cars and drag race cars running the Ford factory Duraspark Distributors and ignition systems and they are happy with them.......

David

I've run MSD on a few cars. Yet to have an electronic issue. I did recently have an issue with the pressed in brass nuts which hold the rotor on, coming loose. Both of them. Had to drill out the bolts.

I have/had all MSD ignition systems in 2 of my cars going back to the late 90's and my biggest problem is corrosion/rust in the internal components in their distributors........
It's no fun to jump in your car and crank it up only to have it missing badly, then have to pull the distributor and take it apart and clean it up.....

I've tried everything MSD has suggested and some things that others have suggested,but living in the gulf south with high humidity all the time, it's a losing battle.........

For the price I see NO reason why they could not/do not coat the internal parts like Ford does with their DuraSpark distributors!!!!!!!!!!

David

My cousin runs the Pertronix in his '32 Ford Hot Rod and loves it. That's a nice all-in-one package. Something to keep in mind for the future.