to all you fuel injection wizards, in need of expert feedback Options

[orange914]

to start let me explain the 914 fuel system as i understand it. please correct me if and where i'm wrong:
1) fuel comes from tank to pump, bottom nipple on pump
2) high pressure out of pump to regulator, middle nipple on pump
3) reduced pressure fuel from regulator loops to and past injectors then back to pump, top nipple on pump




if this is the true operation
i should be able to:
1) mount 914 pump near tank (1969 ranchero v-8). run high quality lined goodyear hose (better than oem vw hose used on 914 system) to 914 regulator (30 psi) say 12 inches from pump output.
2)after 914 regulator outlet (30 psi) install a "tee" in line to return unused fuel pressure. thus "mimicing" the fuel return loop of a 914
3)run 30 p.s.i. fuel from 914 regulator/return tee forward through (stock 3/8" steel line) to 2nd regulator at carb. this dial type regulator would hold pressure to 4 psi at carb
(IMG:style_emoticons/default/poke.gif)
any thoughts/comments on saftey/operation that i might be overlooking (IMG:style_emoticons/default/clap56.gif)

porshe parts in a ford (IMG:style_emoticons/default/rocking nana.gif) (IMG:style_emoticons/default/mueba.gif) (IMG:style_emoticons/default/icon8.gif)

[drewvw]

I think its generally considered to not be a good idea to "pressure down" the stock FI pump to work with carbs. Unless you like fires....

Buy the right fuel pump for the job...

[Mueller]

I think its generally considered to not be a good idea to "pressure down" the stock FI pump to work with carbs. Unless you like fires....

Buy the right fuel pump for the job...

I agree, quit being a cheap @$$ and do it right (IMG:style_emoticons/default/smile.gif)

the 914 pump will have too much pressure and I wouldn't trust the 914 regulator to be able to reliably reduce the pressure needed....if the regulator failed, you could have a major gas fire since now you'd have gallons of gas flowing out of the carb in just minutes...

[orange914]

I think its generally considered to not be a good idea to "pressure down" the stock FI pump to work with carbs. Unless you like fires....

Buy the right fuel pump for the job...

but will this be "pressuring down" or is it actually bleeding of excess pressure? i'm not sure but i think the system is kind of a bleed off (excess pressure). if you think about it, the stock system has the same pressure against it when not in demand. (IMG:style_emoticons/default/confused24.gif)

[orange914]

I think its generally considered to not be a good idea to "pressure down" the stock FI pump to work with carbs. Unless you like fires....

Buy the right fuel pump for the job...

I agree, quit being a cheap @$$ and do it right (IMG:style_emoticons/default/smile.gif)

the 914 pump will have too much pressure and I wouldn't trust the 914 regulator to be able to reliably reduce the pressure needed....if the regulator failed, you could have a major gas fire since now you'd have gallons of gas flowing out of the carb in just minutes...

thanks good points

[bperry]

to start let me explain the 914 fuel system as i understand it. please correct me if and where i'm wrong:
1) fuel comes from tank to pump, bottom nipple on pump
2) high pressure out of pump to regulator, middle nipple on pump
3) reduced pressure fuel from regulator loops to and past injectors then back to pump, top nipple on pump

I don't think the 914 fuel system worked like this.
The 914 pressure regulator is a back pressure regulator.
In other words the regulator goes on the end of the chain and the regulated
pressure is between the pump and regulator not after the regulator.
The excess pressure bleeds off on the far side of the regulator and is returned
back to the gas tank rather than pushing back harder on the pump and outputting
a constant pressure.
The 3rd port on the pump is also routed back to the gas tank.
I believe it acts like a safety valve in case the regulator blocks/fails to keep
fuel lines from bursting/breaking.

While I think you could easily use the 914 pump for what you want to do
with say a nice Mallory fuel regulator that has a bypass return line,
Why not use more modern parts?
I bet you could even sell your 914 FI fuel parts for enough to buy the parts
you need for you new application.


--- bill

[orange914]

to start let me explain the 914 fuel system as i understand it. please correct me if and where i'm wrong:
1) fuel comes from tank to pump, bottom nipple on pump
2) high pressure out of pump to regulator, middle nipple on pump
3) reduced pressure fuel from regulator loops to and past injectors then back to pump, top nipple on pump

I don't think the 914 fuel system worked like this.
The 914 pressure regulator is a back pressure regulator.
In other words the regulator goes on the end of the chain and the regulated
pressure is between the pump and regulator not after the regulator.
The excess pressure bleeds off on the far side of the regulator and is returned
back to the gas tank rather than pushing back harder on the pump and outputting
a constant pressure.
The 3rd port on the pump is also routed back to the gas tank.
I believe it acts like a safety valve in case the regulator blocks/fails to keep
fuel lines from bursting/breaking.

While I think you could easily use the 914 pump for what you want to do
with say a nice Mallory fuel regulator that has a bypass return line,
Why not use more modern parts?
I bet you could even sell your 914 FI fuel parts for enough to buy the parts
you need for you new application.


--- bill

thanks your right, you answered some questions on the stock operation for me. i think your right i need to go with a modern return line set up.
great input guys thanks