1994 Q45 engine bucking/jerking

[logisoft]

Here's the update on my Q. The intermittent bucking returned.Now it happens after I run the car and leave it sit for an hour or so andstart it up again. Although it does come about after I warm the car up,running it for a half-hour or so. When it bucks in traffic it dies and Ijust shift into neutral, restart it on the roll and continue. The problemgoes away within a few minutes and returns to running smoothly. Any ideas?My buddy says I should rent an engine diagnostic machine and look for throwncodes.