1985 745t

Brickers:

There have been some posts on this problem over the past few months (by myself and others), but as yet no resolution. Hoping someone has an idea what it might be.

The problem occurs when the car is started from a cold start and you engage first to begin moving. As you let the clutch out and apply gas the tach begins to drop a bit and the car starts to stumble. Applying more gas corrects the problem, but it seems like I am definitely having to rev more than I should to keep the car from dying.

The car doesn't usually stall (as long as I counter it), it's just weak and feels like it's not getting enough gas. However, I'm fairly sure it isn't a gas supply issue since my fuel system has been almost completely replaced (the only parts in the past 8 montsh are most of the tubing and the main pump).

This problem also only surfaces when the car is cold. If I engage first from a start while teh engine is warm I don't experience the symptoms.

After a a bunch of analysis I'm leaning towards the Hall sensor. Is this a possible culprit? What other sources might I look at? I should also mention that I think the knock sensor might be going and am planning on replacing it. is it possible teh knock sensor is reporting false knock when the engine is cold and triggering a retardation of the time, thus indirectly causing my stumbling?

Any help is greatly appreciated.

Thanks,
rt

p.s. I also considered the IAC as a possible culprit and should clean it to make sure it isn't involved. However, I don't think it is responsible since the tach is fairly stable at idle (maybe a cyclical variance of 50 rpms or so while it idles).