MSD box dead?

[pballance]

Anybody had a MSD 6AL box die on them. Worked on the car a little yesterday, fired up fine but after compression and leakdowns, no spark.

Swapped coils, still no spark. Any easy way to test?

It is still under warranty so I am going to pull it out and send it in but wanted to check it again before pulling.

Thoughts?

[JeffYoung]

LOL....yeah, we've had this happen. Must be a Z car malady.

There is a test. You have to cross a couple of the wires at the box while seeing if you get spark from the coil. MSD website has the test instructions; Ron can also tell you -- he's the wire crosser while I'm just the coil wire holder.

Also, whether under warranty or not, MSD fixes those boxes pretty cheaply.

Note that the only boxes I've seen fail have been mounted vertically. You mount it on the floor, with the vibration dampers, and I've not had any issues.

[pballance]

.........There is a test. You have to cross a couple of the wires at the box while seeing if you get spark from the coil. MSD website has the test instructions; Ron can also tell you -- he's the wire crosser while I'm just the coil wire holder..........

Did that test, still no spark

Also, whether under warranty or not, MSD fixes those boxes pretty cheaply.

Note that the only boxes I've seen fail have been mounted vertically. You mount it on the floor, with the vibration dampers, and I've not had any issues.

Hmmm, mine is mounted vertically on the interior firewall. Maybe time for a change in mounting location

I have done a little more checking and it appears that quality control MAY be an issue. MSD support is good. I guess I will get an RMA and send it back, mostly just wanted to see if others had experienced the box suddenly going belly up.

[JeffYoung]

If you do the test and get no spark, box is bad. Without doubt. When it happened to us, we put in a new box and immediately fired up.

Send it back. Even if out of warranty, the fix was like $30 or something.

[Mike Mackaman]

While MSD makes a very good product and I have one in my Z, they are known for this. The FAA allows their use in Aircraft, but only if you have two boxes, mounted in parallel with a priority switch between them, so the one with a spark sends the spark. Then you have to have another redundant set switched off, ready to go in case the first pair dies. Not exactly a glowing testiment!

Mike

[Dano77]

we had the car warmed up,drove to grid and waited for the checker. The box quit at the 2 min start window,dosent matter how hard you smash the thing on grid it still wont fire.:026: Ran 5 laps on the trailing ign only,not a stellar lap in the bunch. we run redundent pikup wires and have a spare dist in the trailer,weve got a bunch of them. Cheaper than a second box and they do fix them cheap. Another note is the car sat at the next owners house for 5 years and fired off the first try when we got the car back. There is no set reason for the failure,it does that
Dan
70 IT7

[nsuracer]

I have managed to kill 2 MSD boxes. What was finally discovered was that it was an insufficient ground. If they are not properly grounded they will try to make one and burn things internally. When you get your new one, ground it directly to the battery.

[pballance]

I have managed to kill 2 MSD boxes. What was finally discovered was that it was an insufficient ground. If they are not properly grounded they will try to make one and burn things internally. When you get your new one, ground it directly to the battery.

Certainly a good thought. If I recall correctly, it is currently grounded to the negative battery cable at the block.

FWIW, I dropped by the Advance store I bought it from to get purchase date and their reply was "just bring it in to us and we will replace it." As soon as I get it out, I will do just that. Imagine that, good customer service from a chain store!!

Has anybody every wired a MSD box with a switch/relay set up to bypass the MSD in case of failure?

[JeffYoung]

Not sure you can do that. I think the system becomes dependent on the box for spark.

The reliability fix for this is two boxes with a switch, a la Nascar.

Certainly a good thought. If I recall correctly, it is currently grounded to the negative battery cable at the block.

FWIW, I dropped by the Advance store I bought it from to get purchase date and their reply was "just bring it in to us and we will replace it." As soon as I get it out, I will do just that. Imagine that, good customer service from a chain store!!

Has anybody every wired a MSD box with a switch/relay set up to bypass the MSD in case of failure?

[Ron Earp]

Hey Paul,

I am wiring my Z for redundant boxes, it isn't hard. Dual coils, dual boxes and I might use the dual dizzy pickup from a 280zx since the dizzy innards are free. Bought one to investigate. Off season project, I'll help you if you need.

Testing the MSD is easy to do. If using the white wire for trigger bring the wire to ground and then take it off. when you take it off it should spark the plug. If using the purple and green wires short them together, when released you should get a spark.

This guide has a lot of helpful info:
http://www.msdignition.com/uploadedF...pport/WDTN.PDF

[CRallo]

While MSD makes a very good product and I have one in my Z, they are known for this. The FAA allows their use in Aircraft, but only if you have two boxes, mounted in parallel with a priority switch between them, so the one with a spark sends the spark. Then you have to have another redundant set switched off, ready to go in case the first pair dies. Not exactly a glowing testiment!

Mike

this has NOTHING to do with MSD... No matter the ignition system or manufacturer every aircraft is required to have a redundant ignition system...

[Mike Mackaman]

I agree on every aircraft needing redundant ignition. My point is what the FAA calls one system when dealing with MSD. Until you have two, they don't even call that one "system".

Again, I run them and have for a number of years. But they have a known, recognized weakness in that they will just die.

Coasting to a stop sucks in a race. In the air it is worse!

Mike

[kthomas]

[moved]