MSD 6AL Question?

[TN Shelby Cobra]

Has any one ever had there MSD Box go bad? I'm pretty sure mine is going bad. Mark

[Clois Harlan]

Last year about this time mine went out. Heat kills these things. Send it back to MSD and they will fix it for $50. It will take about 10 days but you first must call them and get a return number.


Clois

Originally Posted by TN Shelby Cobra

Has any one ever had there MSD Box go bad? I'm pretty sure mine is going bad. Mark

[Excaliber]

...any one ever had there MSD Box go bad

For some reason that question just makes me chuckle. I'm pretty sure your not the first one around with a bad MSD box.

[twobjshelbys]

My 6A died. It happened right after I washed the engine compartment (note to self, switch off battery kill switch before doing that again.) I futzed around trying to convince myself that it was everything but that - started by replacing the coil hoping for an easy fix. I eventually found the troubleshooting guide at the MSD web site. I did the test to short the coil wire to ground and release and no sparkie. I thought it might be the fuel injection controller which supplies the ignition signal and got an oscilloscope from work and confirmed it was getting the proper input. I ordered a new one and just "dry fitted" it and boom, it worked.

[Dwight]

Lainhart mailed two back to MSD last spring. One tested bad and they repaired it. The other one tested good. I don't think they charged him.

Dwight

[Dwight]

Hey Mark,


I just looked at the picture of your SFP and recognized you. I have that same picture on the wall at the office. We met last June at the Hot Rod Power Tour in downtown Chattanooga.

How are you doing?

I worked my last day at the VW plant Friday. Yahooooooooooooo!!!!!!!!!!

I just remembered I forgot to take the Cobra pictures with me when I left. I'll have to print them again.
Hope to see ya on the road somewhere.

Dwight Frye
Florence, Al

[TN Shelby Cobra]

Thanks for the info guys! I took the Cobra out last week and drove it about 30 miles to a friends house. It was a hot day.Took my friend for a drive after letting it set about 25 minutes. Got on it and it started missing. Took it back to his house and it was running bad and back fring thru the carb. The car started running pretty lean. ( Light grey inside pipes) It doesn't normally run that lean. Went and got my trailer and brought it home . I first thought it might be bad fuel so I changed the fuel filter and drained the tank. Checked the fuel pump ( black inline electric) It is working fine. I changed the carb. ( I was going to do it anyway ) Still don't run. I changed the coil and no difference. (The car has a 392 Ford crate motor ) Car has 7,100 miles on it and I put 1,700 on it since I bought it 4 months ago.The only thing left to change is the MSD box or the MSD billet dist. My box is mounted in the passenger area aboue where you feet are. Its funny cause I took it up to about 6,000 RPM and thats when it started missing like it is suppose to do. ( 6,000 chip is installed) I also pulled the valve covers and everything is fine. I worked on this thing all day yesterday and didn't get no where!!! The past owner gave me all the paper work and the box was been replaced before. ( Car was built in 2004 ) Dwight it is good hearing from you. I have been going to the sonic cruise inn every monday evening. I didn't see you there and figured the heat had got to you from all day at VW!!! I'll let you know when we all get together again down here. Thanks again for all the info everybody. Mark

[madmaxx]

I feel your pain, chased a similiar but not identicle issue and in the end it turned out to be a bad spark plug, what a fiasco of wasted time and labor.

As many MSD 6AL someone needs to come up with a male / female plug kit that you install in your car. that way troublshooting would consist of unplugging one msd 6al and plugging in another one. All my wires are soldered so testing a replacement is a pain since you have to cut all the wires.

[Blas]

Many times, problems with a MSD6AL box can be traced to bad wiring. Check the wire connector crimps on all the connections and the general tightness of the wire connectors to their sources. A loose ground or power can pop the internal fuse in the unit.
MSD has easy to follow test procedures on its web site. You can easily check the operation of the MSD box, the coil and magnetic pickup. MSD boxes are kinda like a switch...either they work or they don't... erratic operation suggests looking for an outside problem - installation or connections...if you have a connection to your ignition switch (most people do) the ignition switch is another source of problems. The ignition switch is also easily bypassed to eliminate it as a problem...Bad wire connections at the coil are also something to check...I heard of them being held together only witht the shrink tubing...
Keep of posted of your progress.

[vector1]

don't they call these the 50/50 box?

[madmaxx]

I was wondering, the MSD test show you if there is a spark at that point in time, but how would you ever check to see if it is working at all rpm's?

[Roush #1]

It's rather expensive, but MSD part #8998 will test your system at all rpms.
J

[patrickt]

I've seen a couple of MSD boxes go bad, but not very many considering how many are actually on the streets. But I can't say I've seen an MSD box go "intermittently bad." It usually either works, or it doesn't. Before you blame the MSD box, undo all connections to the box and clean them (the big red, big black, and skinny red particularly), check your rotor and cap, and try wiggling stuff with a light on the skinny red to see if you can make it blink. I had an ignition switch that was misbehaving on my Cobra and the only way I was able to find it was to put little 12v lights on every step of a circuit and when the misbehavior occurred I could see what lights were lit and what weren't). The MSD pickup in the distributor (assuming you have an MSD distributor) usually fails completely too.

[Silverback51]

They are very sensitive to power input. I have had two voltage regulators go bad, and when they did, the MSD box acted up. It would miss at anything over 2500 RPM's.

While on vacation last month, it started to stumble a little. Found that the negative battery cable was ever so slightly loose. Tightened the wing nut less than an 1/8 of a turn, and all was well once again.

[madmaxx]

MAKE SURE YOUR ROTOR TAB IS MAKING DIRECT CONTACT WITH THE MSD DISTRIBUTOR CAP BUTTON. I have no idea how many times people have run around in circles to find the button inside the distributor cap eaten away because when installed the tab was not bent up. You should have to PUSH the cap down to install.

[patrickt]

Originally Posted by Silverback51

They are very sensitive to power input.

John, that's a great point. If you don't have this MSD capacitor installed, http://www.msdignition.com/Products/...,_26_Kufd.aspx , nuisance voltage problems can not only bug you, but jump starts can kill your box. I'm glad you mentioned that, I forget that a lot of guys do not know about the voltage sensitivity of the MSD box.

[Rick Parker]

They do not like vibration either. Regardless of which model of MSD Box you chose, they are best mounted on the round rubber isolator feet. Mine is mounted in the engine compartment (heat) using the above mentioned rubber isolators, going on 22 yrs, fingers are crossed.

[PANAVIA]

I am not a big fan of MSD boxes. -- they fail at the most inopportune times.

There are alternatives.

[TN Shelby Cobra]

Update on the Cobra problem. I bought another MSD box cause I needed one for my drag car anyway and I put it on the Cobra. Guess what still have the problem. ( But I now have a box for the Mustang) I went back and looked at all the repair invoices that the previous owner gave me. I noticed one where he took it to a Ford dealer a few years ago cause it stopped running on day. The dealer replaced the gear on the distributor. Bingo, I go to thinking what if they didn't know that you have to install a steel gear with a roller cam. I pulled the dist. and there it was a wore out brass gear! I installed the new gear and it is running again!! What a pain for just a gear! Good thing was one of my friends that has a 406 windsor with a soild cam just happened to have a steel gear cause he had to put a brass gear on his since he installed a solid cam! One good thing I got the new steel gear for nothing! Thanks for all the info again! Mark

[Dwight]

What happen to all the brass from the wore out gear??

Dwight