Originally Posted by stevo
start by getting the car serviced or do the service yourself making sure you use the correct grade and gapped spark plugs, new bmw spec air filter, use a good injector cleaner additive (redex) or similar, get your timing checked make sure your belts are tensioned correctly, maybe get your ignition coils checked if you still got lag.
check out the knowledge base here on ub plenty of information there.
if all else fails take it to a reputable garage or main dealers and get a full diagnostic done .
Is there a specific area in this forum that has a "library" of this knowledge base you refer to? I have several electrical issues, and have been searching and searching, but have not been able to find anything. I would LOVE to try and find a complete wiring diagram for my 325E.