Dies in gear, uh oh...

[tylerk]

After posting this yesterday:
http://www.dsmtuners.com/forums/showthread.php?t=176205

I have been messing around more trying to solve the problem. I put the old plugs back in to try to get back to the point where it was last working. Unfortunately, now the car will start up fine and idle fine, but as soon as I put it in gear (reverse, this is an auto), it stalls and dies. I am lost, any ideas?

Edit: also, there's no CEL for this problem.

 

[tylerk]

Just to make sure nothing was really wrong, checked compression and it was good across all cylinders. (Slightly low in #4 but well within spec.)

Oddly if I quickly shift past R into N, car keeps running. If I shift all the way down to L, the tach will drop to almost zero, jump to just over 1k, drop again, rise again, then after a couple of repititions, stabilize at around 6k-8k. If I shift up to 2 or D it's fine, but if I go up to R again, it will die again. A couple of times I got it to keep running (badly) in R for a couple of seconds before it died.

I am baffled!