Fuel Pressure and Pump?

[Whit]

Ideally I would like to find an aftermarket intank pump that could handle a
lot more flow.  Having an inline pump under a jeep is a problem waiting to
happen and there are very few places to really hide a pump. Not much room in
the engine compartment and anything underneath the vehicle is a rock target.

Thanks.
>
> In this case, it sounds like the factory pump may be insufficient.  Is the
> factory LT1 regulator still on the fuel rails?  If it is not
> damaged, then it
> should be regulating pressure to factory levels, provided there
> is sufficient
> fuel volume.
>
> One quick test to check the pump's ability to provide pressure
> would be to pinch
> the return line and watch the pressure rise on a gauge.  If it
> does not rise
> considerably, the pump is not going to work.
>
> You should also check volume.  You can do this indirectly by
> driving with the
> gauge installed and watching pressure changes.  Accelerate, power
> brake, drive
> up a large hill.  If the pressure is consistently at 35 psi, and the above
> "pinch off" test indicates that the pump can build pressure, then
> you may have a
> bad regulator.  But if fuel pressure drops way off, then
> insufficient fuel is
> being delivered to the engine.  Providing the fuel filter is not
> plugged, the
> pump would be the most likely suspect.
>
> If the diagnosis pointed to the tank, I would first try to
> replace the in-tank
> pump with something able to provide enough fuel.  I've had to
> troubleshoot a few
> draw-through, two pump systems, and the in tank pump can sometimes present
> considerable restriction.  If the in tank pump can provide a
> large volume of
> fuel at low pressure, then a two pump system is a reasonable
> option.  But using
> an in-line pump to draw fuel out of the tank can cause problems, imhe.
>
> Shannen
>
> Manuel Desantos wrote:
> >
> > You can run a second in-inline pump with the stock pump.
> > I'd get an adjustable Fuel Pressure Regulator.
> > You can also try and run the in-line and turn off the in-tank pump and
> > see if there is enough flow through the in-tank pump.  If there isn't
> > enough flow then I'd remove the in-tank pump and just run an in-line.
> >
> > -----Original Message-----
> > From: owner-diy_efi at diy-efi.org [mailto:owner-diy_efi at diy-efi.org] On
> > Behalf Of Whit
> > Sent: Friday, January 18, 2002 11:37 AM
> > To: diy_efi at diy-efi.org
> > Subject: Fuel Pressure and Pump?
> >
> > I'm running an LT1 in my 89 Jeep cherokee and am having fuel pressure
> > problems.  I am wondering if the stock fuel pump will do the trick.  The
> > stock pump was meant to run FI on the Jeep at about 35 lbs.  After
> > intalling
> > the motor it is still running about 35 lbs and I understand the LT1 is
> > supposed to run in the mid 40s. I bought a new regulator but my gut feel
> > is
> > that the stock pump is either inadequate or it needs to be replaced.
> > Any
> > have exprerience here?  What are options here?  Can I run a second
> > inline
> > pump?  If so, do I need the stock pump at all?
> >
> > Thanks,
> > Whit
> >
> > ------------------------------------------------------------------------
> > ----
> > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
> > quotes)
> > in the body of a message (not the subject) to
> > majordomo at lists.diy-efi.org
> >
> >
> ------------------------------------------------------------------
> ----------
> > To unsubscribe from diy_efi, send "unsubscribe diy_efi"
> (without the quotes)
> > in the body of a message (not the subject) to
> majordomo at lists.diy-efi.org
> ------------------------------------------------------------------
> ----------
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without
> the quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
>

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org