[Shotimes] fuel pressure regulator and 255lph pump issue

[Paul Nimz]

The simple test is to connect a fuel pressure gage to the valve on the fuel
rail.  With the engine hot and idling the pressure should be around 35 psi.
Disconnect the vacuum line and plug it, the pressure should go up to ~40 psi
which is what is should read at WOT.  The lowest reading is during engine
braking when vacuum is highest and then will be ~30 psi.

But the real test is a 3k to redline blast in 2nd or 3rd gear when fuel demand
is the greatest.  To do this take the Schrader valve out of the fuel pressure
port stem and connect a 4' piece of 1/4" fuel line hose over it using a hose
clamp.  Then connect your fuel pressure gage to the other end of that hose and
wire tie it to the windshield wiper.  Go out and have fun.

Paul




On 9/11/2005 2:13:48 PM, Carl Prochilo (gr8sho@prochilo.myserver.org) wrote:
> You are good at this.  Now, how does one test a FPR?
> --
> Cheers,
> Carl
>
> On Sun, September 11, 2005 13:21, Paul Nimz said:
> > Too much pressure will cause the car to run rich which causes the PCM
> > to trim things back lean and write these values to the data tables.
> > The WOT fuel data numbers are based on the learned real world data
> > which now are biased to lean in the learned data tables.  So less fuel
> > at WOT and too rich when driving normally with a fuel pump that over
> > powers the FPR.
> >
> > Paul
> >
> >
> > On 9/11/2005 11:09:34 AM, Carl Prochilo (gr8sho@prochilo.myserver.org)
> > wrote:
> >> What are the symptoms when the overrun does occur?
> >> --
> >> Cheers,
> >> Carl Prochilo
> >> 92 Ultra Red Crimson
> >>
> >> On Sun, September 11, 2005 10:42, Bruce Malachuk said:
> >> > I've found that the 190lph won't always over run the stock FPR as
> >> a
> >> > friend
> >> > has one in his car and his fuel pressures are where they are
> >> supposed
> >> > to be.
> >> > FWIW I think the MTX
> >>
> SHO's got