SWGSSSlacker

I replaced the stock fuel pump in my 90 LX with a 155LPH (41 GPH) fuel pump thinking it would be more then sufficient for my stock fuel rail with 24lb. injectors.. I understand that 39psi is recommended fuel pressure for 24lb injectors. So, now I'm questioning my decision. Do y'all think the fuel pump I installed is sufficient?

bluebeastsrt

The regulator controls the pressure to the system. Not the pump. Your stock pump could handle 24 pound injectors just fine. What are your other mods?

dawson1112

I ran 30lb injectors in my 90 lx that I use to have with x302 heads, ecam and cobra intake. I had my fuel pressure adjusted to just a hair above 34psi.

88 orangepeel notch

You'll be fine, unless like blue said, your not telling us about the 12lbs of boost your running.

SWGSSSlacker

No turbo or supercharger. Just a fresh 308 with a trickflow streetburner top end.
http://www.latemodelrestoration.com/...op-End-Kit-Blk

Heads, cam, the works.

SWGSSSlacker

I'm going to install an adjustable fuel pressure regulator on it soon. I currently
believe that the stock fuel pressure regulator is somewhat overwhelmed because
the car is running fuel rich. You can smell it at idle just standing behind the car.
I just wanted to make sure that the fuel volume increase (stock 110 lph to 155 lph)
was sufficient for my set up.

bluebeastsrt

If it's old it could be leaking by and time for a new one. Moving up to 24s on a H/C/I car isn't a bad idea. IMO.

64bit

Looks like you are confusing yourself here. The volume that your pump puts out has nothing to do with the regulated pressure in the fuel system.

TBH, an adjustable fuel pressure regulator is utterly pointless while still running the stock fuel rails. Any adjustment that you attempt to make to your fuel pressure, will be compensated for by the cars EFI system. Leave the stock regulator on there.

As for the regulator being "overwhelmed" by the new pump, the easy test is to look at your current fuel pressure. If the regulator can not return enough fuel back to the tank, the pressure in the system will rise. HOWEVER, your 155lph pump is one of the smallest available UPGRADE pumps for our cars. People have run 255lph pumps with ZERO ill effects. The 255lph pump is also the smallest pump I ever recommend putting in.

If your car is indeed running rich, and not adjusting itself, you should consider installing new O2 sensors.

reldla1996

Did you change out the MA sensor to match the 24# injectors? If not, your car would be running rich, as you describe.