Thread: what FPR to run and walbro fuel pump ?

get a nismo fpr. check the pump operating voltage. I have seen as low as 11 volts at the pump under operating conditions. This is caused by the stock fuel pump relay. I always wire a external relay in line with the pump to boost the voltage the 13-14 volts.

ben I thinks he means liter per hour(lph) not low pressure.

Right, but there are variants as Ben mentioned (good catch, Ben). There are low pressure and high pressure 255lph pumps available.

The part number difference is either 341 or 342 for the high pressure Walbro 255lph, and the 317 is the low pressure Walbro 255lph pump. The difference isn't HUGE, but the relief spring in the low pressure pump may not be able to support flow volume at a higher pressure rating (like 20lbs of boost with base fuel pressure at 43psi.)

Thank you ben! Thats what I was trying to figure out, Im currently running the Low pressure 255 lph, its was came in the car and I was thinking I needed a high pressure pump because the low pressure couldn't keep up.

Morgan and tekkie, I don't think its the injectors. When I first put the JWT ECU in the car was running lean from the beginning, I hooked up an safc2 to add fuel and it worked until I started to crank up the boost. Car runs fine dead on at 10 psi to redline. But as soon as I bump up the boost to 20 psi car starts to lean at 5k. Nothing else happens it just starts to read lean. Im thinking the pump can't keep up with boost once I boost more than 10 psi, and Im thinking that if I get an HP pump I can take the SAFC2 back out of the equation.

just a note, Car was also running lean when I had the stock gtir maf in, stock gtir ecu, and stock 444 injectors on 10 lbs. thats why I think its the pump as well.

I would say no. Stocker is fine.

Yah, liters per hour... Duh. Whoops.

The two names for the Walbro 255 pumps always get shortened and misrepresented it's hard to keep up. =]

ben with the 255lph high pressure pump the base fuel pressure increses by 2-3psi. I usually add the nismo fpr to dial out the extra fuel pressure.

NISMO fpr is an awesome piece. i love mine.

I was referring to low pressure pump, thats what im running now and i think its struggling to keep up. Im also running a sard FPR with a gauge on it.

I guess I assumed he had control over fuel injector pulse width. I guess if he ditches the SAFC2 (a good idea) and he does in fact have a JWT ECU then I guess an adjustable FPR is in order.

So I do still need to swap out pumps right to the High pressure pump?