when i drive the car and reach a certain rpm it sounds like the cars not getting enough fuel it boggs down.....and i replaced the fuel pressure regulator, fuel pump, fuel filter, spark plugs, and spark plug wiring.....and before i put in the new fuel pump i blocked of the gas return line and it ran perfect but with the new one it will run but not for long....i cleaned out the gas tank and flushed it a couple times cause it was dirty as hell....but if ne one knows or think the know whats wrong please let me know cause i need this car sold. the car is a 94 civic ex vtec 5 speed

 

wait, so when u block off the return line it runs fine? or just for a little while?

1) try substituting a known good FPR

2) check vacuum connections

3) if u think tank/lines were that dirty, remove/check fuel filter for sediment

4) post again and let us know.