1985 745t m46

Recently started experience a wierd problem that I can only describe as a "driveline vibration." It could easily be something els,e but that's what it feels like.

Basically whenever I get underway from a full stop I generally play the clutch a little to slide it out (standard manual usage, no overplay). Lately when the clutch is partially engaged and I am applying gas I have started to get a shuddering that seems to be coming from the middle underneath the car. The shuddering is most apparent when engaging into 1st or reverse, but is also apparent when rolling into 2nd from a near stop. Further testing has shown it is pretty common across gears under the same conditions (I just see it more in 1st and reverse because of the way those gears are employed).

The shudder feels alot like when the car stalls when you suddenly let off teh clucth without providing enough gas (the shudder lurch in 1st). Problem is I'm supplying plenty of gas given the RPMs and engine sound.

I should also note that for awhile I have been experiencing a wierd near stall when starting from a cold start in 1st. Basically after sitting awhile the brick sometimes has trouble first getting going; I engage first, give it gas, and let the clutch out but it stalls and stumbles a little bit regardless of how much gas I give it. It never actually stalls, but it kinda coughs and just has a rough time of it for a second.

Are these two problems related or am I just looking for a tie that doesn't exist? Could all this be symptomatic of a bad AMM? I have had to reseat my AMM connector a couple times to correct a lean mixture, but it always corrects and then runs fine for quite some time.

Thanks in advance for any help.

Best,
rt

p.s. I should note that all filters (fuel and air) and plugs have been replaced recently enough, oil changes are frequent (mobil1 10w30), and the following possibly related parts have been replaced in the past year or so:

- exh. manifold
- cat
- temp sender
- oil separator
- rebreathe nipple/splitter
- vacuum hoses (all)
- belts (all)
- fuel pump relay
- fuel pump regulator
- various other relays