Lt1 v8 Ms1 ignition help

[Dirt]

New to the forum and im hoping I can get some help here. I have an 85 s-10 with a 4.3 Lt1(baby Lt1) stock 5.7 Lt1 cam. I put this truck together about 4 years ago when I lived in Missouri with my brother doing all the tuning. Last July I drove it back to Denver where I now live. Truck drove all the way back no issues. I was tuning on it the other night and all of a sudden it lost all spark. after doing some chasing I found that it blew the hei ignition module on it. Maybe to shed some light on what im running.
http://www.mez.co.uk/ms9.html I replaced the module truck ran for about 40 seconds and blew the module again. After a couple modules I put a new coil pack on it, new module, redid the module ground and ran a secondary ground from the coil to the head..In case coil was discharging and popping it. truck ran for a while was able to get up to temp and I was about to start messing with the tune and it shut off again...no spark...

I work at a salvage yard so I've gotten some free modules but im down to my last free one and don't want to blow it.
I attached the last datalog when it turned off again, kinda long half way through the truck died when pulling it in the garage, toward the end it died again and you can see me cranking it to try to start with obvious no spark.
Any help or feedback would be greatly appreciated.

2014-08-11_19.44.58.msl

[Matt Cramer]

Can you post a copy of the tune file?

What voltage do you get on the spark output wire with the key on and engine off?

[Dirt]

I will check voltage this evening here is the tune file

s10currenttune.msq

[Faster7]

This is my brothers truck and now it's a long distance diagnosis situation. FUN!

It's been so long since we first put this together.... I'm going to try to find some old configs to confirm that it spent 95% of it's happy life with "SPARK OUTPUT INVERTED=NO" as it appears to be in the current config....

This has a traditional 7 pin HEI distributor installed in the intake manifold, so that module is handling the VR and then the megasquirt triggering the 4 pin HEI module to a late 90's style GM e-core coil---- so no more optispark. It racked up ...... likely 300 miles in >150 short trips over it's first 4 years on that previous HEI module, many of them during short trips with lots of full throttle abuse. Then another couple hundred miles in July getting it ready for him to drive ~720 miles across country, which it did without a problem.

When I walked him through my thoughts with remounting a fresh coil and making sure that the coil body ground / secondary voltage had a good path back to a cylinder head, I really thought we were going to have this thing licked. No such luck!