Hi Guys,
Im fitting the focus st225 engine in my 100e (build thread in projects and restorations)
Im now at the stage where im looking at running the fuel lines etc but it appears there is no return on the fuel rail. After a bit of online research it looks like it has returnless efi ? Is there any way to bypass this as i wont be using the original tank.
You can get a fuel rail with a return from a volvo that will fit in place, would it be worth just changing them?




Any advice would be great

 

anyone?

 

What exactly is the problem ? Or what are you trying to do ?

 

Are you using the standard ECU or an aftermarket one?

 

Basically i want to know if i can somehow still use the standard fuel rail and try and make it work with what ive got, but i imagine i would have to have the standard fuel tank to link it all up with all the bits inside?

this might explain it better
http://www.aa1car.com/library/returnless_efi.htm

I have all the original engine loom and its all connected up, just have to splice it to the ecu. I intend on using an aftermarket ecu, the vipec v88.

This is pretty much the last piece of the puzzle so any advice is appreciated.

 

I still dont see the problem ? And highlighting the above, we arent mind readers. What have you got ?

If you're using an aftermarket ecu, and have a normal fuel tank and pump, then what is the problem ? Just fit a pressure regulator and job done ?
Where is the difficulty ?

The FPR can be anywhere on the pressurised line and the weblink you posted clearly shows how easy it is with very clear drawings of each system.

So what exactly dont you understand ?

 

you not use any T5 or Audi jobbies mate?

your focus motor is volvo, which is Audi by design

***Edited*** just read the full post again,
Use Volvo one mate, job jobbed!

i wouldnt trust a regulator before the rail as number 1/5 will have different pressure IMO

 

sorry yeah my bad
So i just have your basic fuel tank suitable for any normal return injection system.

So i can take off the sensor on the fuel rail and make that the return? simple as that? Thats all i wanted to know as plumbing it in with the return is straight forward.

Cheers

 

yes, bin that crap and fit the Volvo return with the propper regulator at the other end to hold pressure!

or an Aeromotive adjustable jobbie, easily modified to use this, if your stuck PM me and i can help pass some details and pics on matey, hope the 100e is coming on well

 

The FPR can go ANYWHERE on the line from the pump to rails. Or simply at the end of the rail as most older conventional systems do.

If you mount it before the rail and leave the rail dead end, just tee off to the reg and return back to tank as normal
It is a very simple setup no matter what way you plumb it with pros and cons to each way. But the FPR certainly does not have to go after the rail.

 

nice one, thanks for your help, has cleared alot up.

 

with 2 totaly different answers, i bet it has

 

The Vipec is capable of running a returnless fuel system. I've recently mapped a Time Attack Mini Cooper S with a returnless fuel system on Vipec, its just a case of treating the fuel pump like a fuel injector and giving it a larger duty cycle at higher loads/engine speeds. That increases the fuel rail pressure when you need it, its not as difficult as you'd think!

 

Or just fit a regulator and run it as normal.

Can the Vipec control the pump directly ? how does it handle the current ? What sort of PWM frequency does it run the pump at ? ( assuming the Vipec actually controls pump speed in order to maintain correct pressure and no regulator at all is used )

 

I'll have a look at the map file tomorrow and check, this particular ViPEC had been made as a 'Plug & Play' onto the standard Mini Cooper S wiring loom so was preconfigured in a lot of areas. I had to adjust the duty in a few places.

A lot of returnless systems also run a fuel rail pressure sensor so with the right programming can run a closed loop system to maintain a constant pressure.

 

Unless the car itself already has a controlled and the Vipec just uses it.

There are a few ways pressure can be controlled without a regulator. Pressure monitoring is one, as is current draw from the pump.

But a lot do still use a regulator in tank as the above image shows to a degree