msd issues 6al and 8594 distributor

[wrench87]

So I went to take the cobra for a ride today and it would not start new 445 fe only has 500 miles on it same for 6al box and 8594 distributor. I had my spark tester in my jeep so i checked no spark , performed test at box and it sparked
pulled cap the carbon electrode is flush? i dont have another cap to compare to.

I checked the resistance of the pick up just shows open ?
I do have a toggle switch under dash that grounds out white wire but can not get to switch with out pulling dash due to under dash panel.

I am thinking module ? any ideas

[Rick Parker]

If the pickup is open without ANY resistance you have a bad pickup.

84661 Magnetic Pick-up for Pro-Billet Distributors Magnetic Pickup, All MSD Billet Distributors 500 - 700 ohms

MSD Ignition

[patrickt]

Originally Posted by wrench87

I checked the resistance of the pick up just shows open ?

The resistance should be within 500 - 700 ohms. So, that's certainly a red flag Try shorting across the magnetic pickup wires (Violet and Green) with the coil wire about half inch from ground -- the wire connector for that is about six inches or so down from the bottom of the distributor cap. When you short them, you should see a nice spark.

[wrench87]

seeing that I only have 500 miles on this new distributor should I take the chance on another msd pick up or could I install a stock one?.

Does any one know what type of screw head is used to mount the pick up?, I want to try to remove the pick up with the distributor installed.

I owned the distributor for a few years so it is not under warranty even though it sat in the box?.

[patrickt]

Originally Posted by wrench87

seeing that I only have 500 miles on this new distributor should I take the chance on another msd pick up or could I install a stock one?.

Does any one know what type of screw head is used to mount the pick up?, I want to try to remove the pick up with the distributor installed.

I owned the distributor for a few years so it is not under warranty even though it sat in the box?.

It's mounted with plain old normal screws and nuts. See here for pics of when I tackled a rust problem: MSD Distributors - Here's Another Thing I Don't Like I would just slap in a new MSD pickup -- it's not a big deal.

[ERA 778]

Sounds like your center electrode on the cap is shot. It should protrude about 1/8 inch or more (don't remember exactly). Mine went at about 500 miles as well. I believe it was because there was insufficient pressure on the center contact on the rotor. If there is a gap there, the arcing probably destroys the carbon very quickly.

Hal

[Rick Parker]

If you replace the pickup the screws are Stainless socket head cap screws with mechanical lock nuts securing the magnet. It is somewhat dificult to do without the distributor removed. Adjusting the Air Gap between the Reluctor and the pick is tedious and must be precise or the trigger signal will cause irratic ignition and misfiring. Use a brass feeler gauge or baring that try a matchbook cover .015 thick. Doing this right is not as easy as you might think.
FYI the new screws and nut come with the replacement pickup from MSD. It is difficult to clean the remaining adhesive and silicone potting material out and replace the wires without being able to spin the advance mechanism to access the area. Good luck

[wrench87]

Does any one have a good picture of the center tab on the inside of the cap.
I thought I could save some time by not pulling the distributor, I can check the gear while I have it out. Is there any one local that caries the msd pick ups?.

[patrickt]

Originally Posted by wrench87

Does any one have a good picture of the center tab on the inside of the cap.
I thought I could save some time by not pulling the distributor, I can check the gear while I have it out. Is there any one local that caries the msd pick ups?.

Here you go. This cap had about 3,000 miles on her, IIRC.

[wrench87]

After seeing your picture mine is worn, how do the stock chevorlet caps hold out?. Does any one have a part number for a aftermarket cap?

[patrickt]

Originally Posted by wrench87

After seeing your picture mine is worn, how do the stock chevorlet caps hold out?. Does any one have a part number for a aftermarket cap?

If you pull the tab on the rotor up, and you put a light dab (NOT a glob) of dielectric grease on the terminals and center ball, you will get a good 3,000 or more miles on the cap, be it red or black. Don't forget to drill some holes for the ozone. This old thread of mine, A Better Looking MSD Distributor Cap , I believe has part numbers for non-MSD caps.

[mtpockets]

I experienced this at least 3 times on my MSD distributor. I even talked to the MSD guys at SEMA in '11 about this issue, he gave me his direct line and address asking me to send him the next one that did it. The center electrode on the cap breaks off. The car continues to run as the signal is hot enough but it will eventually wear down the spring pickup on the rotor. Of course, since I met him I've had no failures. I do carry a spare cap and rotor with me always.

[wrench87]

I posted on the msd forum about my pick up issue and the msd tech guy is sending me out a new pick up thanks msd. I dont understand why a msd pick assbly is cheaper then a msd distributor cap?.
I was at pep boys a new cap is 36.00 and a new pick up is 29.99 ?.

[streetrod1927]

I just tried to fire up my Cobra as well last night... had fuel, had plenty of battery power too. That big 427 FE S/O turned over like no other.... Down side it never started. What a bummer as it was the first warm day we have had in a while!! I am going to test for spark today and check out the center pick-up as well. I have been reading posts that seem to be directed to this problem. I am running an MSD 8595 Ready to Run Distributor and MSD coil with 8mm wires and Autolite 45 plugs.

[Rick Parker]

Just a bit of my experience. I run resistor plugs at a gap of .045 no wider. I am also hard headed an continue to run solid core wires with no apparent detrimental effects other than creating havoc on the radio of the car next to me in traffic . I have no other electrical accessories other than a Msd Rpm limiter that plugs into the MSD 6T Box. I route the #7&8 wires in such a way they do not create any cross fire. I do see some "rust" created on the magnet core and attaching screws but I occasionally attempt to scrub it with a small stainless wire brush and blow out With compressed air. My crankcase is well vented an I don't have a lot of Blow By that can and would otherwise be forced to some extent past the seals within the distributor and contaminate the atmosphere within the cap. I have never had the center electrode disintegrate. My personal thoughts are that this is caused by the electrical loads imposed by the combination of resistor plugs, resistance type wires, high powered coils and wide plug gaps. I do see some "fluffy" deposits on the brass poles within the cap and on the end of the rotor but it poses no problems and is easily cleaned. In the 25 years I've had my car I have had the same MSD box on it. I once thought the box had failed but it turned out that when replacing the pickup assembly I had installed the magnet upside down and thus changed the phasing and polarity causing triggering problems between the distributor and the box.
The only item that has to be watched closely is the dimension between the reluctor (star wheel) and the field coil pole of the pickup assy. You DO NOT want the reluctor to become magnetized so it is suggested you use a brass feeler gauge when setting the gap. If you check with MSD you will get one of many different answers for the correct air gap dimension. I use .015 for a strong signal.
Personally I think MSD is a well designed product overall.

[zrayr]

Originally Posted by patrickt

If you pull the tab on the rotor up, and you put a light dab (NOT a glob) of dielectric grease on the terminals and center ball........"

Not really a good idea. Dielectric grease does not promote the flow of electricity, it impedes it. It should be used on areas like spark plug boots, the plastic or rubber parts of electrical connections, but never directly on wires or metal terminals.

There are many legitimate sources that will tell you the same thing if you do a google search of dielectric grease.

http://en.m.wikipedia.org/wiki/Silic...lectric_grease

http://m.wisegeek.org/what-is-dielectric-grease.htm

Z

[Clois Harlan]

If your car has sat for awhile take some rubbing alcohol and a white paper towel and wipe out the inside of your dist cap. Condensation will build over time. Especially since you only have 500 miles on your car this is a likely cause of not starting.

[patrickt]

Originally Posted by zrayr

There are many legitimate sources that will tell you the same thing if you do a google search of dielectric grease.

And many sources that well tell you that it improves connections. It is not like putting an insulating piece of rubber or glass between two connectors. MSD recommends it, and the tech sheet for the dielectric grease recommends it (Permatex, for instance) and prescribes putting a light coat directly on the connector. It will not inhibit the connection. And, in 30+ years of doing it, I've never had anything but good results from it. But, I won't try and sell you, please don't use it if you're uncomfortable doing so.

[zrayr]

You may have been putting it on metal connections for many years, but they are working inspite of what you are doing, not because of it.

Z

[patrickt]

Originally Posted by zrayr

Young have been putting it on metal connections for many years, but they are working inspite of what you are doing, not because of it.

Z

Well, I'll see that and raise you two MSD Tech posts. There are countless others....