my civic was turbo until just recently. i got pulled over and now i have to see a smog ref. my car's all back to stock now except for the exhaust and fuel pump. I was about to change that back to stock too, but then i started thinking i probably didn't need to. will having a 255lph fuel pump on an otherwise stock car cause it to run rich? according to my a/f ratio guage (i know, i know), for what it's worth, it's right on the border of stoich and rich all the way to redline. I figure i shouldn't need to put the stock one back in because there's nothing telling my fuel pump to pump more than stock.

so bottom line: is it necessary to put the stock fuel pump back in to pass emissions testing, or at least to run clean and well?

side note: anyone been to a smog ref? how thorough are they? are they likely to notice that i have the stock intake plumbing off a gsr stuffed onto my throttle body?

thanks, guys

 

if your fuel pressure regulator can work correctly with the bigger pump, no need to change.

But a stock FPR cannot bypass enough to control pressures to below 50 psi with a 255 LPH HP Walbro.

 

What fuel pressure roughly would the stock fpr run then with a 255 LPH HP Walbro?

 

From what I've experienced, the stock FPR can't get any lower than about 50-53 PSI with the walbro installed.

Ryan P.