Map sensor make sure it's connected well

Start there

 

When the problem occurs, does the engine rpm go up , stay the same , etc

 

I'm pretty sure it's what Feezy said: I'm not letting it warm up enough before I gun it. Rpm doesn't go up, it just shuts itself off for a second.

 

The grinding hasn't occurred as violently recently and the engine thing hasn't happened for awhile since I'm making sure it's warmed up.
What I'm concerned about now is the misfire since it's probably not just the coil pack, which I thought it was.

 

if the valves were adjusted too tight it will cause a miss. ive seen this alot. if you have the means you can graph the map voltage and watch the waveform to determine if it's an electrical or machanical miss. a nice square wave pattern is an electrical miss and a jagged up and down(like a heart monitor) is a mechanical miss.

 

Nice work, never thought about that