My N/A B230F in my 1995 940 is skipping & missing at idle & taking off from low RPMs when the engine is warm. I've replaced spark plugs with no change, checked fuel pressure(38-40 at idle & 38 when revving, holds steady at both), I've unplugged the idle air valve to see if it changed anything but it didn't. I will be changing the fuel filter tomorrow to see if that helps but I'm honestly at a loss.. Help?

 

Leave that Fuel Filter alone, it's not the problem! Most likely it's the fuel pump, if the "tune up" related parts are all in good nick.

 

small air leaks in the intake path can cause stumbling at idle and at low RPMs, that will generally smooth out once the engine revs up some, because they make it run too lean at said low speeds.

 

Would that show up on a vacuum gauge? I hooked one up & it was running about 20hg at idle.

 

whats the spark plug wires, cap and rotor look like?

 

One of the plug wires were bad... Ohm'ed them out & found #1 to be low resistance.