starting... and slugish

[B318M42W]

I don't know why, but it takes forever to start the engine. 2 months ago, hot/cold it started on the 1/4 turn...  now, it takes about 5-10 seconds of cranking to get it going hot or cold. however, if i cut it and restart in the following minute, it starts right away. also, if i turn the fuel pump off, it will stall within 2 seconds (as before it took about 5-10 seconds).  It also feels sluggish on accel.

Recent parts replaced: Fuel pump (used), fuel pressure reg(used). fuel filter(new). i use shell 91 for gas

thanks for any input!

[bearsbmw]

sounds like a weak fuel pump

[B318M42W]

finally got down to ''digging in'' and found that i had air bubbles passing through the fuel lines... swapped the fuel pump hanger and fixed the bubble problem, however, the no-return valve is busted so fuel does flow back into th tank via the fuel pump. guess i need a new valve...