Fuel line plumbing ????
 

I am just about to start doing the parallel fuel line conversion and fitting an adjusatble FPR.

From what I can see and determine:

The feed from the pump/fuel filter goes into one of the metal lines attached to the passenger side of the inlet manifold, I can see it then goes to the rear of the fuel rail on that side-through the rail and then comes out of the front of it and basically under the manifold to the other fuel rail.
Somehow it will link up to the front of the drivers side fuel rail, through it and out of the back via the original pressure regulator and then back to the tank.
My question is:

If the standard set up has a feed and a return why are there 3 metal fuel lines on the passenger side of the inlet manifold, what is the 3rd one for ?

It might become clearer once I have the manifold off though I just wanted an answer before I set out on the job.

Thanks

Third one (alot smaller) is the tank vent which goes to the carbon canister.

Here is a diagram of my setup.

Hope its of use :)

http://www.scoob.co.uk/rebuild/fueldiagram.jpg

Its now slightly changed in that I no longer have the T on the return line.
I have two return lines to the reg (one from each rail) and then one from the reg to the tank.
http://www.scoob.co.uk/rebuild/fuelsetup.jpg

Cheers

Daz

Thanks for the answers guys, oh and Daz if mine turns out to look like yours I will be well happy:)

However 3 more questions have now arisen from your answers:

1) If i decide to ditch the carbon cannister, what do I do with the open pipes ?
just bung them up with a bolt or similar?

2) Daz, for set up purposes where do you fit the pressure gauge now you are using both inlets to the FPR ? If you fit an inline gauge, is it in the feed or return pipe.

3) the tank vent pipe with your non return valve on ? I presume you install the valve so the tank can breath as it is emtying but nothing can come back out, in other words the arrow on the valve pointing back towards the tank.

Thanks again you are being really helpful.

The tank vent which goes to the carbon cannister has a one way valve on it already (I think its right near the carbon cannister).

Do not 'Plug' the other pipes you take off, as they still have to vent.

1. Bung them up with rubber grommets should be fine.

2. If you havent already bought the FPR i'd go for the fuel labs one. This has a gauge port on it. If like mine you have no gauge port you simply T it into one of the return lines after the fuel rails but before the regulator. Do not do it after the reg and before the tank. The gauge needs to be installed after the rails but before the reg.


3. The arrow is other way round I think. You want to vent from the tank but not let anything return to the tank. so the arrow points away from the tank indicating direction of flow iirc.

If he vents to atmosphere the tank breather pipe at the bulkhead where it comes into the engine bay the breather pipes are totally disconnected so it wont matter if they are bunged up or not.

I thought he was talking about the other pipes which go to the carbon canister, Map sensor vent etc.

I thought they vented back to the inlet? Its that long ago since i did mine

Me too!!

From what I can remenber there were 3 pipes to the carbon canister, one from the Fuel tank, one from the map sensor and one from the Blue solenoid on the back of inlet mainfold (can't remember what that was:wonder: )

Has anyone got a definitive answer on removing and replumbing the carbon cannister then.
While I have got the inlet manifold off I might as well do the whole job.

Block the fuel ones off and leave the others vent to atmosphere.

REMOVAL OF CARBON CANISTER
 

Hi there,

I am also doing this mod. I have already purchased parallel fuel rails, fuel pressure reg and all the fittings.

At the moment I am in the process of removing the carbon canister. The inlet manifold is off so easy access.

1. There are three lines that go to the carbon canister. Two at the top and one at the bottom. I have removed them all and taken out the canister.

2. I understand that the non return valve is to be connected to the vent line near the bulk head next to fuel lines. I have seen pics from another thread.

3. The purge control valve situated under the manifold has also been removed but what happens to the vent line from this and the inlet manifold? and what happens to the line that was connected to the bottom of the purge tank.

I have searched through other threads but none show clear pics of this mod from start to finish.

Any help would be much appreciated.

SC

What to expect before installing my parallel lines....
 

Hi everyone,

I recently bought a RCM parallel fuel lines kit for my 2006 STi and was wonder, before I remove the lines off and everything, has anyone seen a right up on this kit or have any advice?

Getting my hands on a proper manual has been hard too and I was wonder is it easy enough to deal with this third vent line for the tank? Has anyone just left it open, or will I see a non return valve in the line once I get the manifold/lines off?

Just want to be prepared BEFORE I do the job!!!

I'm also doing this mod. I have taken away all the pipes under the manifold all together because I don't need them. I'm gona bung the returnline from the standard dumpvalve since I have a atmospheric dumpvalve now. And the ventilation between the valve covers and turbo inlet will be connected with silicone hose and a t-piece connector.

But I'm not sure how to do with the tank breathing hose. Should I connect it to the valve on the back right side of the manifold and then connect it to the manifold so it vents into the manifold. Or should I vent it to the atmosphere from the valve or just disconnect the valve and vent to atmosphere directly?


Getting rid of the pipes give me nice space under the manifold and it frees up the turbo inlet so its much easier to put the manifold and turbo inlet on.


http://www.djfoto.se/bilder/subba/motor2014/32.jpg

http://www.djfoto.se/bilder/subba/motor2014/33.jpg

I had read up somewhere else that you can either connect it to the manifold as described here....(there is a good picture at the bottom)

http://www.iwsti.com/forums/2-5-lite...es-arrows.html

OR

other people have said that you literally use the blue non return valve that is already there in the line and vent to atmosphere. That way tank pressure is released, but the tank can't pull a vacuum and draw into the tank. Im going to go for this method first as Im sure re-circulating fuel vapour from the tank into your inlet manifold will not be the best for emissions and no doubt wouldn't do the combustion process any favours.

I will use the valve and vent to atmosphere then. My valve is black/green and sits on the back of the manifold och the right side seen from the front of the car. You can see it in the pictures in my last post.

Thats a good move!

Just to help out, I bought some AN adaptors that are male on one side and barbed on the other....they let you connect your new rail lines that normally have AN Female connections, to your stock fuel lines as they enter the engine bay from the fire wall, near the battery.
Got them from Torques UK on Ebay, got decent reviews and were half the price as compared with Earls etc. Also, managed to get a male/female gauge adapter there so you can fit an 1/8NPT gauge in the line for setting up the base fuel pressure until you get a remap done. Handy stuff!

Yeah I know about turque :). Ive order a lot from them :). As you can see on my pictures I already got that type of adapter :).

HEHE good stuff, I just noticed now lol

How did you find the job overall? Im an engineer myself and pretty handy but haven't really got into the really detailed jobs on the engine yet. Was the manifold removal/install straight forward enough? Im just planning on marking eau hose/part I remove....kind of like engineering by numbers to help match it all up installing again!

I am an mechanic so it's nothing hard. It used to be a pain in the a** to install it since the turbo inlet was pretty non movable with the the stock fuellines installed. But when I trail fitted the inlet manifold this weekend to see so everything was clear it was a piece of cake since the turbo inlet is so movable now when the pipes are gone.

Thats good to hear. Yeah I have a rotated turbo, so no inlet to worry about, but there but it will be probably be a nightmare re-routing some of the water cooling pipes that run around the manifold now!

I can smell a wee bit of petrol occasionally so Ill defo need to change the injector O Rings too while I'm at it! Trying to do as many of the larger jobs at once so now might be a time to remove the A/C as well!!

To remove the fuel breather:

Right, there are two vents on top of the tank. These both have rollover valves which prevent leaks if the car tips.These two vents go into one pipe and then travel down the nearside sill under the carpet alongside the supply and return line.

In the engine bay the vent pipe goes under the inlet and into the charcoal canister. The charcoal canister has three outlets.One to the pressure switching valve on the offside suspension turret and is branched to the inlet pipe post MAF. One to the purge valve on the rear of the inlet manifold which then is connected to the throttle body. The third outlet is underneath the canister and vents to atmosphere.

To properly delete:

1. Vent the tank vents to atmosphere. You don't want to block them as it will prevent excess pressure getting out. You can either vent to atmosphere under the bonnet or even better back near the tank. I binned the metal hard line that runs back to front along the sill and vented to atmosphere just in front of the tank.

2. Bin the canister.

3. Bin the under manifold pipe.

4. Block/blank the hole in the underside of the inlet pipe post MAF.

5. Remove the pipe from the pressure switching valve and blank off or remove the T piece.

6. Blank the throttle body nipple.

7. Leave the purge valve connected electronically to prevent a CEL light but loop a small pipe over the two nipples on it to prevent dirt getting in it.

The system is now fully deleted and you have no leaks.

If you simply VTA the breather line you will end up with all those pointless bits in your engine bay. Please note this is how it works on classics (MY00) it may be different on later models with the canister near the tank.