The Worlds Slowest 24v E30 - now with MORE SPEEDS

[Jake]

And I guess the fuel pump could be going out intermittently but from what I understand its more of an immediate once and done failure when it comes to pumps.

The one in the E46 coughed once, made it about a mile before starting to give up for real, and was totally dead about three blocks later. I would think it's something that isn't the pump, in your case.

How old is the fuel filter?

My E30 (Eta) would do roughly what you are describing, in 1st or 2nd gear and seemingly at random. Not a "bog" but just a total lack of power for a brief second. My theory was rust in the tank that was blocking the "screen" on the pump if you jostled the car around just right. I sold the car with the issue and am not sure if the next owner figured it out - he continued my thread on here so click the signature link and maybe give the last few pages a read?