Yesterday I finished installing all new fuel system on my car. 2000 civic with a b18C. Walbro 255, rc 310 injectors, blox fuel pressure regulator, blox fuel pressure gauge on the filter and new tuned ecu from phearable step down to obd1. Using a stock fuel rail.

I checked for leaks and started the car and the fuel pressure was reading 55 psi. I could not adjust the blox fpr any lower, only higher.

I changed to a stock Ls fuel pressure regulator and the pressure read 60psi.

I changed the gauge to a no name I found in the garage and the reading is the same, 60 psi

I blew air through the return fuel line and the tank bubbled so I'm assuming the line is not clogged, and the fuel filter was new 6 months ago. Any ideas?

 

I have never used one but have read nothing but bad reports about the Blox fuel pressure regulator.

 

I've read half good half bad about them but I tried it. But I'm having the same issue with the blox regulator and the stock Ls regulator.

Another thing I forgot is that the car seems to be running good and my wideband o2 sensor is right about 14.5-15.5 at idle even though the fuel pressure is reading 55-60 psi, that doesn't sound right to me...

 

Send phearable an email and he will let you know what fuel pressure the map was tuned for and go from there I know RC injectors dont like alot of fuel pressure.

 

I sent them an email and they said 42-45 static, with the hose disconnected.

 

Are you saying you cannot get the pressure below 55psi using the Blox FPR?

 

it can only be 2 things... restricted return line or bad or improperly adjusted FPR.

Try disconnecting the return hose just off the regulator and have it dumping into a bucket and see of the pressure drops as you adjust it. If it doesnt drop as you loosen the preload on the regulator, then youve got a bad regulator. If the pressure drops when you unhook the return hose, then youve got a restricted return line.

 

^^^ that's a great idea, thanks. I don't know why I didn't think of that, so simple, I will try that when I get home from work and post results

 

I did the trick mentioned above, took the return fuel line hose off and nothing changed, so I bought a new aem fpr and fuel rail why I was at it. Installed them both and again nothing changed. I changed from the small orifice to the big one, nothing changed.

I ended up taking the walbro 255 fuel pump out and putting stock back in, solved the problem, I'm not sure how the pump could cause high pressure but that was the problem for me. So I have for sale a walbro 255+ model if anyone is interested, ill let it go for cheap haha