Bogging down at 2500 rpm

[Faceman]

Well, I have finally run into something that I am not able to track down and I'm looking to see if this has happened to anyone else. Car is 92 e36 318i, M42 engine, recently (last couple of weeks) the weather has started to get colder and now every morning when heading out to work this is what happens. As the engine hits between 2500-3000 rpm the car bogs down like it sputtering and not getting enough power, shift to 2nd and its good till it hits 2500-3000 rpm and it does it again. Shift into third and keep it below 2500 rpms for a about 3-4 miles till it warms up, than everything is fine and is normal again. Sucks having to short shift a putting down the road till it warms up. After its warm there are no problems. This was not happening when the weather was warmer. I am not sure what is happening with it, anybody have a clue?

[DesktopDave]

Hasn't happened to me yet...I'd check for water or ice in the plugs/wires/coils when the car has sat overnight, that sort of thing.  Once the motor warms up it'll drive out the water & run perfectly again.  When the motor cools off it'll condense water & freeze overnight, causing momentary shorting.

Why 2500rpm though?  Did you do a stomp test to see if you're getting any codes?

[Faceman]

Haven't done the stomp test yet, but I'm on vacation tomorrow and Friday, planning on working on the cars, this one has first priority. Will do the stomp test tomorrow morning and see what I get. No water around the plugs/wires/coils. Car stays in the garage at night. Yeah, I'm boggled.