Fitting a fuel pressure gauge to an LS1 (VTII)

[r2160]

All

I have a VT SII with the C4B 5.7.

I understand there is the valve on the end of the fuel rail that is for using a large gauge to check the fuel pressure. However, I would like to fit a fuel pressure gauge so that I can see what is going on while I am driving.
Is there a fitting that I can put on that to fit a fuel pressure gauge in the car? If not, what is the best way to fit one? I want to fit an electric gauge.
Thanks all

 

[robbhibb]

That valve is only used for static testing as it bypasses the regulator and can not be used driving. You will have have a T piece made to fit between the fuel rail and the feed line. This will have to be custom made to suit your gauges lines and be mechanical or big bucks to fit a dummy injector plus wiring plus calibaration etc

 

[Bigfella237]

Assuming your system doesn't have a return line back to the tank, the fuel pressure is constant anywhere in the system after the fuel pump (in a return type system it's constant anywhere between the pump and the regulator).

So you should be able to connect a gauge anywhere in the supply line or fuel rails, just make sure that any fitting you use in the line doesn't restrict it, and that all fittings/lines/sender/gauge/etc. used are rated appropriately for the fuel pressure (most likely 4 bar (58 psi) but you need to allow up to about 100 psi).

Andrew

 

[07GTS]

fuel pressure testing kit simply unclip from firewall connection then thru the line/gauge/back to fuel rail then have the gauge under the windscreen wiper as u drive, this is only for testing and there should never be a gauge in the vehicle with fuel pressure in it, i have a small one on my fuel reg which is handy but u dont need to see it all the time

 

[Jxfwsf]

At most you would fit a gauge under the hood where you can check it occasionally when needing it to diagnose an issue.
In that case as suggested put it between the injector rail and fuel supply hose, and mount it close by on the inner guard/shock tower.

The factory regulator is in the tank and there is no fuel return line, if you plan on running meters of fuel hose around the engine bay, through the firewall and behind the dash in the car with you. It's unroadworthy, dangerous and illegal to have any fuel lines inside/passing through the vehicle cabin.

 

[axemurderer101]

https://www.aeroflowperformance.com/af146-02

 

[r2160]

All, I ended up fitting an AF146-02 as you suggested and I am getting 46-48psi fuel pressure. From what I read, that is a little low. Should I be looking at the fuel pump?

thanks

 

[07GTS]

pressure should be same from pump to injector rails any loss is a loss to the whole volume, all LS use 58psi except new ones with variable pressure so it's a bit low could be pump or reg getting tired, what's it like under load does it dip lower or stay constant ?

 

[r2160]

It remains relatively constant, however, I think one or more injectors are actually leaking. If I leave teh car sit, I get unburnt fuel out of the exhaust on startup. I have pulled the injectors and they are getting cleaned and checked before I do much else. I also found that the seals on the intake are stuffed, so I am going to replace those as well. I will then recheck the pressure and see where I am at.

 

[jigz]

All, I ended up fitting an AF146-02 as you suggested and I am getting 46-48psi fuel pressure. From what I read, that is a little low. Should I be looking at the fuel pump?

thanks

Whereabouts exactly does the AF146-02 connect to? Is it at the intake side of the fuel rail?
I have a VX.