Problems with MSD ignition - what could it be?!

[buba6]

OK, so now I am giving up. Need to ask for your ideas. I have a 302 supercharged Mercury Comet with a MSD ignition set. It includes:
- bilet distributor with dual pickup
- MSD 6 box
- MSD Boost Timing Master
- MSD blaster coil
- MSD spark plug wiers
All of those are connected as a separate wire installation, heavy red wires are connected directly to the battery, the small red wire is connected to battery with a switch in the middle, ground cables are directly to the battery.
Some times I get perfect spark, starting the car couple times in a row and no problem, than it seats for example for 30 minutes and doesn't want to spark any more. I have replaced the 6 box with a 7AL, the same result. Kicked out the BTM and fired only on MSD 6, the same. When I am shorting the wires comming from distributor, eliminating it, exactly the same, sometimes sparks, some times not.
Any idea what could it be? It is extremly hard to build a musclecar in europe, importing all the parts from USA and waiting for them weeks, and now this!
Please help!

[bmbrzmn101]

The small red wire should be from your ignition switch. The wire from the car harness that was attached to the positive side of the coil should work. Recheck that all connections are correct per MSD's diagrams. If they are correct you will need to start checking for lost grounds or continuity of the wires or connectors. Hope this helps.

Chris

[H2Ogbodies]

http://www.msdignition.com/instructiondownload.aspx

Search for how to test the pickup coil-that always seems to be MSD's Achilles Heel. I don't think their quality is going anywhere but down since almost everything they have is made in China and has been for the last 8-9 years or so. And since they own Mr Gasket Company now.....future ignition options are getting limited.

[buba6]

I have the small red wire connected to a batery through a switch. so it works like an ignition switch. I first switch this on and than crank the engine.

The cable wiring was done again as new two days ago, so it is ok, checked the voltage on the cables.

As for the pickup in the distributor, I am overpasing it by using a cable and shortening the plug that comes from MSD box, as in the troubleshooting instruction.

Every time the same, once I have perfect spark, once nothing.

[H2Ogbodies]

You should be able to use a standard LED circuit tester-clip ablead to each end of the pickup coil connector and crank the engine over. If its good, the LED should keep flashing-if it does not, prolly a bad pickup.

[buba6]

some Times it flashes, sometimes it does not. I did that test. When it does not flash, I disconnect the pickup and shorten those two cables and sgain sometimes it flashes, sometimes it dont.

[H2Ogbodies]

If it doesn't consistently flash, I'd say the pickup is bad or the box isn't sending a consistent signal.

[buba6]

pickup is eliminated so it isn't the problem. It hapens with 3 different boxes, so I doubt that 3 are bad.