That sounds like mine did when I couldn't get the MAF to fail in a SD tune. I finally gave up on SD with the E38 because it couldn't get the MAF to fail consistently. When it would fail, it would run fine.

It also acted like this when:

A shredded belt hit the MAF plug and pulled the signal wire for the MAF out.
When I failed to PIN a LS7 Maf correctly.
When I blew the intake piping off with boost.

Other thoughts. My 08 will still run with the cam sensor unplugged. It sounds like you are getting spark for a second. Crank sensor?

 

I had all kinds of fun with making my own stand-alone E38 and T42, just like this one

I have experienced the "no cam sensor" issue before. Yes it's getting spark.

it's got a Viper alarm on it, but it seems to be working just fine.

I'm open for suggestions.

 

Spray some starting fluid in the intake when you start it to see if you can keep it running...

 

I'll try it out

 

it's alive.

I loaded a tune from another e38 and t42 setup.

I can only guess that the original file got corrupt or who knows. . . . . well see what happens next.

I'm just glad that it's nothing mechanical that I did and ended up being something tune related.

The PVC intake was just for testing, it's nothing permanent.