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MSD 6A Install Help! *Update* Attempt #2

Chevy305

Chevy305

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I am currently installing an ignition box and I can't get the engine to run. I have an MSD 6A box and a MSD Street Fire HEI. I have gone over the wiring 20 times and I have even called MSD tech help and confirmed it to be correct but its still not running. Every couple of cranks the engine fires once and thats it. The LED on the unit lights up on key on. I can't figure it out! Anyone with some advice?
 
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Been a while since I installed mine but if you've gone over the wiring with MSD tech, sounds like you got something else going on.

Sounds like time to break out the test light, voltmeter and yada yada.
 
Just make sure to have the latest updated Yada Yada.........
 
I'm kind of curious if he has the small red wire off the 6AL hooked up that has full power with the key on AND during cranking.

Sounds like the 6AL is not getting power during cranking.
 
4X4HIGH said:
Is the dizzy a new install or are you only adding the MSD 6A?
Click to expand...

The distributor was in there since I installed the engine.

JDNobodi said:
I'm kind of curious if he has the small red wire off the 6AL hooked up that has full power with the key on AND during cranking.

Sounds like the 6AL is not getting power during cranking.
Click to expand...

The small red wire is hooked to the distributor power wire
The small orange wire is hooked to the B+ terminal
The small black wire is hooked to the C- terminal
The ignition module was removed and the purple and green wire hooked to the magnetic pickup
The white wire is unused
The gray wire is hooked to the RPM input signal wire for the ECM
The big red wire is hooked to a terminal strip fed directly from the battery
The big black wire is hooked to the negative battery cable

I have confirmed battery power and coil power to the box. I even tried to re-install the filter for the ECM RPM signal which was required when not using an ignition box.

In the morning I am going to confirm that I have a good tach signal to the ECM, then I don't know what else to do. :sign22:
 
You have done the spark test, right?

Remove the coil wire from the dizzy, put it close to a ground. remove the green and purple wires from the pickup. Turn the key on, and use a small jumper wire to short and unshort the green and purple.
Every time you break that connection, you should see a spark.

If not, try a different coil. It may not be able to handle the extra voltage.
 
Fordum said:
You have done the spark test, right?

Remove the coil wire from the dizzy, put it close to a ground. remove the green and purple wires from the pickup. Turn the key on, and use a small jumper wire to short and unshort the green and purple.
Every time you break that connection, you should see a spark.

If not, try a different coil. It may not be able to handle the extra voltage.
Click to expand...

Do I short the box side or the distributor side? I tried this on the box side and I got no spark but the led on the box would come on and off as well as the led on the ECM then the fuel pump would kick on and off with the ECM. This doesn't make any sense?
When you say short the coil wire do you mean the orange wire right?
 
No no....
Its just like you would normally test for spark on a point system. Put the coil output wire, (plug type wire) next to a ground to watch for a spark.
Leave everything hooked up except for the green and purple wires.
Unhook them from the distributor, and short and unshort them with the key turned on.
All you are doing is imitating what the pickup in the distributor does. You are telling the box that the engine is cranking even though it is not.

Every time you break the connection on the purple and green wires going to the MSD box, you should see a spark from the coil.
 
Its been a while since I did any of this. Let me see if I can find a diagram.
 
Right now, I gotta take a couple of pills I'm overdue for this morning, and then go outside and work on a boat before it gets too hot.

I'll check back in about an hour or so. Hope to see you got it running by then.....
 
I don't have a coil wire, I have an HEI with the coil in the cap.
 
Ok I have confirmed the ECM gets a good tach signal from the box. Now I'm going to pull a spark plug and see if there is spark.
 
Ok so I have no spark so I swapped the coil with a good spare and still nothing! MSD tech line is closed and so is summit racing till Monday. I have no idea what the problem could be! Ugh this pissing me off
 
Ahh, you and your darn Chevys. I was thinking separate coil........

You would not necessarily see a spark at a plug, unless the dizzy was pointing at it when you fired the coil.

You could pull the coil out, leave the wires hooked to it, and put a grounded conductor of some kind next to the spring contact on the bottom of the coil.

I figured the ECM was getting a signal from the box, since it was turning on the fuel pump.

I would suggest a test light across the output of the box to the coil, but it fires with about 450 volts, so you would only get one test before the bulb blew.

At this point, we need to find a way to tell if the coil is firing and when.
I would try to rig up a spark gap to the output of the coil.

Either with it out of the dizzy and a grounded screwdriver laying next to the spring, or it in the cap with the cap removed and the screwdriver laying next to the center post of the cap.

Once we have a way to test for output, then we need to try it with just 12 volts. Pull the input wires off the coil, hook the negative one to ground, and lightly tap a +12 volt wire to the positive terminal.

Everytime you do, you should see sparks from the output.

If so, then leave the spark gap the same, hook up the two wires from the box to the output of the box, and then short across the green a purple wires off and on with the ignition on.

The ECM should see the tach signal and act accordingly, and the coil should fire each time then too.
If the coil works with 12 volts, but not with the box, then either the box is bad, or neither of the two coils you tried can handle the increased voltage.
 
Ok so here's what I found:
I set up a spark gap on the coil output by leaving it connected and pulling the coil up and putting it on its side. I jumped the purple and green wires and got 1 spark. That's it. Every time I jump it the ECM triggers the fuel pump and every time I jump it the led on the box goes out when I release the jump it doesn't come back on until you cut power and turn it back on but sometimes it comes back on on its own. To be sure it wasn't a bad connection or otherwise I jumped the little red wire directly to the battery and still no change.
 
Well, unless someone else has an idea, it sounds like you got a bad box.

Since there is not anything you can do about it today, if its not too much trouble, either try hooking the coil up to 12 volts directly and make and break the contact to be sure the coil is actually firing, or find some other style coil and try it with the box.

Like I say, that box puts a much higher voltage pulse out than normal, and there are some coils that cannot handle it.
But, if the red LED goes out, and it will not fire again until you pull power, it sure sounds like a bad box.

I know you hooked up the small red wire to a good power source, and I am assuming that you know your ground is good, but you mentioned that the white wire was not hooked up.
That is correct for your setup, but it can be used as an engine kill switch by hooking it to ground.
As long as its hooked to ground, the engine will not run.

Any chance it got pinched under the unit or something?

Also, there used to be someone here who was an vender for that company I think. Not a clue as to who it was, and not sure if there is a way to search for them.

Maybe someone else remembers who it was, and will let us know. If they are still active but not on much, you could send an E-mail.
 
OK, its official. I'm an idiot.
I just got through watching this guy fix another member's MSD problem here. Even posted in the thread.

He has a good rep here, and got the other guy fixed right up.

Here is the thread to check out.

http://coloradok5.com/forums/showthread.php?t=298962

His screen name is Philly87 He was last on here on the 19th. I would either send him a PM, or an E-mail.
I'm betting he can get it straight.
 
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