Misfiring;sluggish in 1st gear

[CS III]

I just purchased a 1992 325i with about 150 k miles.
It's has an M50 engine. The engine doesn't appear to burn oil and overall it appears to be a good vehicle. However, it idles very rough and misfires occasionally. When I put the car in drive and accelarate it is very sluggish under 40 mph unless I completely depress the pedal. The vehicle also idles and drives very loudly. I don't expect top flight performance from a 14 yr old car but seems something is not right.
I did try to check the spark plugs ( I replaced them with platinum Bosch 2 plugs with no improvement). The DME or ECU (the electronic control unit) was supposedly replaced in Nov. of '05 and I have the reciept of work done.
Could it be the plug wires or coils?
I welcome any suggestions!!!!
Thanx

[Wayne 962]

Hi there and welcome. Your first step is to check the codes that the engine may or may not be giving you. See my article for details on how to do this:

http://www.pelicanparts.com/bmw/techarticles/Mult-Code_Reading/Mult-Code_Reading.htm

Then, let us know what you find out...

-Wayne