MSD 6AL dying?

[Scott Liggett]

Im wondering if my 15 year old MSD 6AL box is on it's way out. Every now and again, when I try to start the car, it spins like there is no spark. You know how the engine seems to spin faster when there isn't spark to slow it down or fight the compression.

At first, I thought I just flooded. But, the usual fixes to get a flooded engine started don't work.

After a few minutes of sitting, the car will start right up.

Also, my tach jumps about when I first start it up. After a couple minutes it starts to work normally. The tach is getting it's signal from the MSD. The HEI does not have a module in it. The box replaces that.

[SuperBuickGuy]

I just put one in my Corvette, and had one in my Skylark... the Skylark one never gave me trouble; have you done a quick check to make sure all the connections are still solid?

[TC]

Yap connections and grounds are the place to start........

[TheSilverBuick]

My setup does that too from time to time. Hmm, I've been blaming the efi box, but it shows rpm when cranking and perhaps I've been chasing my tail and its the msd box not sparking... I guess I'll know for sure when I go to coil on plugs if it starts quicker.

[Barry Donovan]

tach jumping, and then the box suddenly works later..
multi spark may be helping something not so friendly to get out.

first use ever for me, as a defense. I do like that stuff.(I got what I swear is a radon climbing out of a damn street drain)

given how simple they are, they either work or not.

on my accel box, I found a diode right on the case..
maybe after checking connects, get a look at box.

if it is the monster I am theorizing, there can be zero errors.

[squirrel]

I'd look into the ignition switch first, maybe connect a light bulb to the wire that feeds the "run" signal to the MSD box. Then if the light is off when you're cranking, you know the switch is getting flaky. If it's on, the ignition is probably flaky, or there's a dry carb or something.

[TheSilverBuick]

I'd look into the ignition switch first, maybe connect a light bulb to the wire that feeds the "run" signal to the MSD box. Then if the light is off when you're cranking, you know the switch is getting flaky. If it's on, the ignition is probably flaky, or there's a dry carb or something.

Interesting, I'll have to try that. It's getting power straight from the old HEI power wire.

[milner351]

I've had MSD fail, mine just quit, nothing intermittent - I sent it back to them and they fixed it and sent it back. That's why I always leave the module intact in case I have to bypass the msd on the side of the road some place.

The ignition switch is a great place to start - as usual - Squirrel FTW.

[dieselgeek]

Tach bouncing is an indication that the MSD is having a hard time tracking the incoming crank position signal from your distributor. Look closely at any connections for the (is it purple and green?) wires coming from the dist going into your MSD box. Sometimes a worn cap, rotor or wires will cause spark noise to bleed back into the distributor's pickup sensor causing similar behavior.

[TC]

It's in the Box..... Here read this.....

http://www.msdignition.com/forum/showthread.php?t=9075

[dieselgeek]

It's in the Box..... Here read this.....

http://www.msdignition.com/forum/showthread.php?t=9075

Thats it? Problem solved? LMAO.

[TC]

Thats it? Problem solved? LMAO.

What he needs to do is read how they are testing the box, which I'm sure he'll understand.........

[TC]

By the way DG lets see how up you are on your MSD, when running multiple MSD Boxes(6AL, Engine Builders Delight, multi step retard, etc....) how do you connect them all together??......

[dieselgeek]

By the way DG lets see how up you are on your MSD, when running multiple MSD Boxes(6AL, Engine Builders Delight, multi step retard, etc....) how do you connect them all together??......

If you want to see how "up" I am on anything, check the winners list for Drag Week. Otherwise, ill take your questions when YOU are building something that'll run.

Now let Scott have his own place to ask questions, start your own in a "Theory racing" section somewhere else.

[TC]

If you want to see how "up" I am on anything, check the winners list for Drag Week. Otherwise, ill take your questions when YOU are building something that'll run.

Now let Scott have his own place to ask questions, start your own in a "Theory racing" section somewhere else.

Figured, you don't know.....

And this is not rocket science, it's going to be a bad connection in the wiring, a bad MSD Box or a bad pickup in the distributor, and maybe a bad cap and wires(unlikely)........

You people try to over analyze everything, Remember KISS, Keep It Simple Stupid.........