msd 6al help please

[jlkendri]

I have a msd 6al that has ran great since it was finished a couple years ago. MSD distributor. It suddenly is getting no fire. None from the dist. and none from the coil. Checked for voltage key on for both small and large red wires, all good. Did trigger test with white wire shorting to ground and getting good fire from coil with test. What is my next step? Thanks

[timp2]

Log on to MSD's web site and check their support information. If you have the instructions from your install I believe that you will find a way to just bypass the red MSD box and run voltage directly to the distributor, if you dont have the instructions they can be found on the web site. If it works when it is bypassed then the box is faulty, if it does not work the distributor is most likely faulty. Hope this helps

[MikeKelly]

Ok, personal experience here:

Check ohms (resistance) across the coil terminals (disconnect the wires from the MSD box).

It should be around 5K.

If it's open you need a new coil, buy this one:

http://www.summitracing.com/parts/MSD-8222/

HTH,

Mike

[happybigblock]

Most likely the trigger in your distributor. Many of us have had the same exact thing happen. The MSD 6ALs are known for this. When the magnetic pickup goes bad, the unit does not know when to send out the spark so it essentially goes dumb and won't fire, even with everything working correctly. Most of us either change the magnetic trigger annually or keep a spare with us. Cheap insurance.

This is the pickup/ trigger I use. http://www.shopatron.com/content/shopping//424.0.1.1

I buy mine from the local Advance Auto or any place that sells MSD.

-Steve

[jlkendri]

ya, the more i read, the more i'm thinking it's the trigger too. i have the "ready to run" dist. i think is what they call it. Are they too bad to change out? Thanks to ALL of you that answer these forum questions. You help a lot of people out.

[jlkendri]

ok, now i'm really confused. Checked the resistance on the magnetic pickup and it's 541 ohms which is within range of what msd says is a good pickup. Thats between the black and red wires on a ready-to-run distributor.

[MikeKelly]

What ever you do - Do not try to check the voltage coming from the MSD box to the coil.

A- A Fluke meter won't read it.

B- It's up there around "electric fence", if you get my meaning.


Don't ask me how I know...

[Greg_M]

You triggered the box by grounding the white wire and releasing it and the coil sparked. That's good. Now, in the same manner, test the magnetic trigger input lead coming from the box by shorting and releasing the green and purple wires together. This simulates the trigger that is supposed to come from the dizzy. It should produce a spark from the coil. If it does not, then the box is the problem.



BTW, what's the model number of your dizzy? Are you using the white wire from the box to the dizzy or the mag trigger plug with the green and purple wires.

[jlkendri]

thanks greg. i will try shorting the green and purple. i'm not sure on the model number, i will have to look. But its the "ready-to-run" dist. with 3 wires coming off it. I'm using the white wire as a trigger. The magnetic trigger plug is not used the way this one is wired. Which leads me to think since it's getting spark from shorting the white wire that all is working but it's not getting a trigger signal from the dist (white wire). Therefore, you would think it would be the pickup but, if i'm doing everything right, the pickup checks out ok. I don't know man. I couldn't call msd this weekend cause they were closed but i'm gonna call them today. thanks

[jlkendri]

ya mike, thanks for the advice, i've gotten it off a lawnmower and that was enough love for me. I hate getting shocked.

[Greg_M]

A dizzy with 3 wires needs switched 12V and Ground. Verify them. The remaining wire should trigger the MSD box, goes low (to ground) when the pickup is triggered.

Really dumb question but is the rotor turning when you crank the engine?

Greg

[jlkendri]

i've got 12v and ground but what i didn't check is how much voltage i'm getting with the starter engaged, i just checked it key on (about 11.8). I have an optima battery but it's several years old. Guys at parts store said it was still a good bat but it may be dropping too much voltage with the starter engaged. I appreciate the advice. I'm gonna mess with it some tomorrow and I will be sure i'm getting 12v to the dist. Not sure about the rotor I will check it tomorrow. I'm getting spark from the coil grounding white wire but not getting spark from coil from box turning over starter so maybe i'm dropping too much voltage engaging starter. Don't guess you know how much voltage I need? Btw, you got a fine car there Greg! thanks.

[EdwardR]

I had 3 MSD boxes go bad due to a voltage surge from the old style regulator Im using to maintain the period correct look. I was told the MSD is analog and will not handle too much change in volts so I went with the digital Mallory and problem solved..

[Greg_M]

Thanks on the car! 11.8V means the battery is not fully up. 12.6V is a normal battery fully charged after sitting for a day. The MSD box will fire at 10V or less. Why not put a charger on it for a while and get the battery fully up to eliminate one variable.

Greg

[jlkendri]

ya, i'm thinking along those lines too. Except the optima on it now is about 8 years old so, though i haven't had any trouble with it, i have decided to just get a new one anyway to eliminate that variable. Gonna try to pick one up tomorrow. I don't think that's the problem cause when it initially happened i jumped it off my truck with a good battery but 8 years is just waiting to fail anyway.

[jlkendri]

I guess it was the battery. strange. the starter motor turned over fine but i bought a new battery and so far so good. thanks for the help.

[Greg_M]

cool.