94 530i no power

My 94 bmw 530i was running great, then went from 60mph to 20mph. It idols fine but when you push on the gas pedal it bogs down. I put a mass air sensor in, did not help. Any one have an idea. Thank you

I'm going to guess maybe vanos solenoid or fuel pump(filter)also possibly because it's drive by wire I believe could be air valve servo not opening hope that might jog a solution other than that I'm stumped too.:crying:

Thank for the info. I just replaced the fuel filters, did not help. What did help was unpluging the mas air sensor, runs bad, but I can go 55mph.