Malpassi fuel pressure regulator ?

[zross1]

So at idle my fuel pressure is at 3-4 psi on a rx-1. I tried adjusting the Malpassi fuel pressure regulator, but no matter how much I turned the adjusting screw in or out my fuel pressure won't change. I checked this with two different fuel pressure gauges. Shouldn't I be able to adjust my fuel pressure up or down fairly easy? My wideband is showing good a/f's so I don't know if it's a big deal anyway.

Also which way of turning the adjusting screw is up in the fuel pressure, and which way is down? I assume out turns the fp up and in should turn it down.

 

[lakercr]

So at idle my fuel pressure is at 3-4 psi. I tried adjusting the Malpassi fuel pressure regulator, but no matter how much I turned the adjusting screw in or out my fuel pressure won't change. I checked this with two different fuel pressure gauges. Shouldn't I be able to adjust my fuel pressure up or down fairly easy? My wideband is showing good a/f's so I don't know if it's a big deal anyway.

Also which way of turning the adjusting screw is up in the fuel pressure, and which way is down? I assume out turns the fp up and in should turn it down.

Back off the jam nut and tightening the set screw will increase base fuel pressure. If you are doing this and not seeing an increase you either:

Have a bad regulator
Are picking up the fuel pressure signal from the wrong spot

Where did you tap in for FP?

 

[zross1]

I'm picking up fp from the bottom outlet hose from the fuel pressure regulator.

 

[RED]

You need to check before the reg coming from the fuel pump

 

[rxwarrior]

The bottom is the return line if I remember correctly. You need to tap the side where two lines come from the regulator and go to the carbs.

 

[RED]

Brain fart , between the reg and the carbs

 

[zross1]

Thanks guys, got it figured out. I just didn't turn the adjustment screw in enough the first time.

 

[ultimate]

the MALPASSI regulator with boost application work fine if you change the spring in.

it was the problem that i got with this reg, but now work fine!
bye

 

[goggle]

Which spring did you get for the regulator? I find my spring very hard.