No Spark!

[MCOULTER]

I'm running the MDS 6AL package in my Superformance cobra. I recently lost spark (no spark at the plug wires and no spark from the coil wire). I sent in my box, distributer w/plug wires, and coil to MSD for testing and all came back good. I am hot to my MSD box with both red wires. I am not hot with the red wire coming out of my box to the coil but MSD says that it will not read hot (sounds odd?).

I'm lost at this point. I have checked everything in line there is to check.

Any thoughts?

[Rick Parker]

Check the triggering mechanism, IE distributor, sounds like the module may be dead. With everthing installed, and key on, disconnect the 2 conductor wire coupler to the distributor. With car out of gear, pull the lead from the coil to the distributor cap and lay it near a good ground (still attached to the coil) Use a short jumper wire and touch the two prongs in the coupling that was disconnected from the distributor,each time you break the circuit you should see spark at the grounded coil lead. If not check your swiched 12 volt source.

[Tommy]

Make sure the rotor is turning with the engine. If the distributor shaft/gear is broke, you'll get nothing.

[MCOULTER]

Originally Posted by Tommy

Make sure the rotor is turning with the engine. If the distributor shaft/gear is broke, you'll get nothing.

The distibuter was checked by MSD. It is also cranking the engine so I have eliminated a mechanical issue with the distributer. Let's take a step back...In order to get spark to the plugs I must first have spark coming out of my coil wire which I don't. Yes, MSD checked the coil & wire and found it to be working properly....

Does anyone think it is odd that MSD told me the orange (hot) wire going from my inginition box to the coil will not test hot with a wire tester?

Love electrical problems!

[CHRIS DAMSCH]

This summer my MSD 6al was working on and off. Sometimes it ran like a champ and other times no spark. I did MSD's tests off of their website. Sometimes it worked, other times it didn't. Finally, it just ended up the box completely gave up. Put in a new ignition box and the car fires right up and runs perfect.

Maybe it's an intermitted problem with the box?
Does the car crank, but just no spark?

[Tommy]

My simple minded understanding of this ignition system is that power goes to both the distributor and the ignition box. When the rotor in the distributor reaches the closed position, it sends a signal to the ignition box telling it to energize the coil. The ignition box then sends a series of pulses to the coil through the orange wire you asked about. That, in turn, sends high voltage pulses from the center of the coil back to the distributor where it is directed to the correct spark plug wire by the rotor. ... I do not know if the pulses from the ignition box to the coil can be detected with your wire tester. I also do not know what you mean by, "It is also cranking the engine so I have eliminated a mechanical issue with the distributer." If the cam gear teeth are stripped or the camshaft is broken, the distributor shaft will not turn. So I ask again, have you confirmed that the rotor spins when the engine turns over?

[Bobcat]

Maybe I missed something here . Did you check the spark at the coil wire to ground with the engine not running per the MSD test ? Or was this when you were cranking the engine .Go back to square one and do one thing at a time . As Tommy said , is the distributor turning ? Seems obvious , but a friend owns a garage and you would be surprised how many people say their car just quit running and they just were out of gas .... not saying that`s it , but sometimes the problem is so obvious we can`t see it .

[Blas]

12V won’t be present at coil + is because your MSD ignition is a Capacitive Discharge Ignition...
Go to the MSD website and read the tech paper "Checking The MSD Ignition For Spark" - A simple test...Next I would look at the mag pickup tech paper "Magnetic Pickup in the Distributor" another simple test.
Other possible causes would be cap and rotor not properly installed...Bad ground on MDS box. Bad connections on wiring (especially at coil where actual attachment of wire is hidden at metal connector end... The two tests above will tell me a lot...

[davecobra]

I would take the dist cap off and check to see if the rotor is turning, the windsor engine is famous for breaking dist gears and you think you have a bad box but all that is wrong is the gear has stripped or broke and is no longer turning when the engine is turning.
David

[Rick Parker]

Again:

--------------------------------------------------------------------------------

Check the triggering mechanism, IE distributor, sounds like the module may be dead. With everthing installed, and key on, disconnect the 2 conductor wire coupler to the distributor. With car out of gear, pull the lead from the coil to the distributor cap and lay it near a good ground (still attached to the coil) Use a short jumper wire and touch the two prongs in the coupling that was disconnected from the distributor,each time you break the circuit you should see spark at the grounded coil lead. If not check your swiched 12 volt source.

If it works when doing the above the box and power to it are OK, If not check the individual power leads, the large red one and the small red one that switches the box on. Do the same test over.
If it works the problem is now confined to the trigger mechanism, (the distributor) either the module, the connections to the wire loom (two pronged plug) or its not spinning as others have suggested.

[mkassab]

check all grounds.... i.e., eng to frame and Ignition box

Mark

[MCOULTER]

Thanks for all the advice. Hope to get back under the hood this weekend and post my findings.

[Roscoe]

How about the coil?

[Scufty]

Magnetic pickup ! Thats what mine was ..cheap part easy to replace