Pete,
I to found out that voltage to the pump is important when fixing a Rover
oneday.The pump was making a lot of noise and the motor was starving for fuel so
i replaced the pump with a VL only to find it was still starving for fuel. after
a lot of mucking around I found that the Rovers have a resistor hidden in the
dash that drops the voltage to 9 volts.I bypassed this and the problem was
fixed.
Andrew Smith
Pete & Kath Liebig wrote:
> Craig,
>
> Sounds fair. Next time I'm fiddling with the fuel system I'll do some
> experimenting.
>
> I still reckon 1/4" lines would be OK though - at 6.35mm that's still 1.35mm
> larger than the pump outlet, so hopefully that would allow enough for
> frictional losses. Only one way to find out though....
>
> By the way, I did some testing when I installed the new pump and came to the
> conclusion that one of the most important things to watch out for is voltage
> drop. Make sure the pump is getting close to it's full 12 volts or flow
> drops off markedly... I have the figures if you're interested.
>
> PL
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]] On Behalf Of Craig Overend
> Sent: Monday, 1 January 2001 17:28
> To: [EMAIL PROTECTED]
> Subject: Re: FJ Fuel line advice needed
>
> Pete,
> one thing to remember is depending on how long the fuel line is, you
> will see a pressure loss at the outlet end of the line. Just try blowing
> through a short and long piece of same ID hose and you'll definately
> notice the difference. So just because the pump will flow 250kW through
> its outlet doesnt necessarily mean a line X metres long with the same
> internal diameter or slightly bigger will flow the same. Using a line
> that is small may flow enough for the engine but is more likely to
> overload the fuel pump and overheat/wear it out causing failures.
>
> To do it properly you would do all the fluid mechanics maths, however
> alternativly try the following, I have not tested this method as I just
> came up with it, I havn't allowed for pump efficiency but the following
> might work.
>
> Measure the pump current using an ammetre when loading the pump up to
> the required pressure using the pressure regulator directly at its
> outlet. Then install the pump on the fuel line and regulator at the fuel
> line output and measure the current using the regulated pressure. You
> should then be able to tell if the pump is being overloaded from the
> current difference and calculate what % bigger flow rate of line you
> need.
> Say at 12V the pump consumes 7.5A at 60psi with no fuel line.
> Say at 12V the pump consumes 10.0A at 60psi with 5mm fuel line 3 metres
> long.
> Ratio difference = 10.0A/7.5A = 1.333
> The flow area of 5mm diam line = 5mm X 5mm / 4 * 3.142 = 19.637mm�
> 19.637mm� * 1.333 = 26.177mm�
> Square_root(26.177mm� / 3.142 * 4) = 5.773mm
> So Using a 5.773mm diameter line the pump will be much happier with more
> flow potential and last longer at 60psi.
> You could alternativly use the fuel pressure difference from the pump
> outlet to the fuel line outlet to calculate the % bigger flow rate
> required.
> Any comments welcome.
>
> With any EFI conversion you should test it using a fuel pressure gauge
> at the outlet of the line after you install it.
>
> Craig.
>
> Pete & Kath Liebig wrote:
> >
> > Bruce,
> >
> > The outlet on a Bosch EFI pump from the VL turbo is only 5mm in dia. And
> > these pumps will support up to 250Kw, so unless he intended getting more
> > than this from his engine then 1/4" lines should be fine. I know it seems
> a
> > bit small, but I really can't see any reason to go bigger than the pump
> > outlet. Pump inlet dia is another story...
> >
> > PL
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]] On Behalf Of Bruce Ferguson
> > Sent: Friday, 29 December 2000 20:35
> > To: [EMAIL PROTECTED]
> > Subject: FJ Fuel line advice needed
> >
> > List,
> >
> > A young bloke I saw at the wreckers today wanted a
> > 1600 fuel line for his FJ conversion. (I was securing
> > a set of ventilated rotors and twin spots)
> >
> > I advised him that it was not big enough and 5/16" was
> > more on the mark. Was my advise correct and what about
> > the return line dia ?? the same ????
> >
> > Cheers
> >
> > Bruce
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Yahoo! Photos - Share your holiday photos online!
> > http://photos.yahoo.com/
> >
>
--membersozdat-------------------------------------------------------
OZDAT Mailing List Please Note:-
Send (un)subscribe requests to [EMAIL PROTECTED]
Send submissions to [EMAIL PROTECTED]
No unauthorised redistribution of this email
http://www.ozdat.com/ozdatonline/index.htm
http://www.ozdat.com/ozdatonline/listindex.html
http://www.mail-archive.com/[email protected]/
---------------------------------------------------------------------
