wild bill Posted July 22, 2009 Share Posted July 22, 2009 Due to age, despite Rob Walker kindly telling me how to plumb my FP regulator on the 2.3 Duratec with a non return fuel rail about 3 times i have forgotten as everytime i call him as i'm about to install it something takes me away from the install and when i come back it all looks confusing again. The regulator is an Alpha i think and has one pipe out the bottom and one out the side and then a tiny one to vent i assume the bottom pipe goes to the fuel pump and the side pipe to the filter but where does the t piece go to return unwanted fuel, between regulator and pump or regulator and filter or does the t piece go between pump and filter with the regulator sitting between the t piece and the return to tank? I'm mighty confused Link to comment Share on other sites More sharing options...
Paul Deslandes Posted July 22, 2009 Share Posted July 22, 2009 See if this jogs your memory Bill. The filter should go in line after the pump and before the injection system so I would expect the order to be: Pump to filter IN Filter OUT to 'T' (any port) 'T' to side entry of regulator 'T' to fuel rail Bottom of regulator return to fuel tank The thin pipe is an air bleed and usually left disconnected but NOT blocked. This means that the fuel is fed from the pump, via the filter, to the fuel rail and the regulator via the 'T' piece. The regulator allows excess fuel to return to the tank and maintains a constant pressure at the injectors. It doesn't matter how you connect up the 'T' piece so long as it feeds fuel to the fuel rail and the regulator. Not sure about your specific regulator but some have a second side entry which means you can do away with the 'T' piece as the two side entries are commoned together. Even so I'd stay with the 'T' piece as, if you do have a second side input, its useful to connect a pressure gauge for adjusting the fuel pressure. If you do have one it should be properly blanked off, otherwise you'll have fuel gushing out when the pump's on 😳 Hope this helps and agrees with Rob's instructions. I'm assuming that the Alpha regulator works in the same way as most others by returning excess fuel to the tank. Paul Edited by - Paul Deslandes on 22 Jul 2009 16:20:38 Link to comment Share on other sites More sharing options...
wild bill Posted July 22, 2009 Author Share Posted July 22, 2009 Thanks Paul I thought the regulator went prior to the filter (this would make fitting easier anyway!)and that the feed in to the bottom of the alpha was from the pump rather than the side feed being from the pump. i'll print this out so i don't forget Link to comment Share on other sites More sharing options...
Rob Walker Posted July 22, 2009 Share Posted July 22, 2009 You are correct Wild Bill the tee goes before the filter infact I would put it near the end of the tank the branch goes to the side connection on the fuel pressure reg then install a pipe onto the bottom connection and run back as a return to the top of the tank. You can then do away with the fuel return line from the engine bay. Link to comment Share on other sites More sharing options...
Colin Mill Posted July 22, 2009 Share Posted July 22, 2009 Is this the right pdf here? page 15 seems to have a plumbing diagram. Link to comment Share on other sites More sharing options...
Paul Deslandes Posted July 22, 2009 Share Posted July 22, 2009 Interesting way of connecting up Rob and it certainly has the advantage of shortening the return. My only concern would be the pressure drop along the fuel line from the regulator to the rail. As the flow increases with throttle I would expect to see a drop in pressure at the injectors which the regulator can't detect and correct for. Perhaps not sufficiently significant to out way the neater installation. Paul Link to comment Share on other sites More sharing options...
Rob Walker Posted July 23, 2009 Share Posted July 23, 2009 Paul, The ford fuel rails are single ended ie they only have one connection being fuel in. All the latest Caterhams are plumbed this way. I take your point that it would be better to site the reg after the fuel filter but as you know the fuel pipe after the filter is steel so this makes this difficult. In practise there isn`t a problem with any pressure drop along the line. Rob Link to comment Share on other sites More sharing options...
Colin Mill Posted July 23, 2009 Share Posted July 23, 2009 Inertial considerations (rather than viscous ones) might just be worth a quick sum. If there is no form of fuel plenum in the rail then, as an injector opens, there must (because of the incompressibility of the fuel) be a drop in the pressure at the injector in order for there to be a pressure differential between the input of the pipe and the injector to accelerate the fuel in the pipe up to the required flow speed. To do the sum you would need to know the length and bore of the pipe from the regulator to the fuel rail and the peak flow rate through the injector (the latter would need to be doubled if the ECU pairs the injector drives as some systems do). Link to comment Share on other sites More sharing options...
Rob Walker Posted July 23, 2009 Share Posted July 23, 2009 Colin, The system is proved by Ford and Cosworth, why look for a problem that isn`t there? The early Ford fuel rails used to be equipped with a damper but this is now deemed no longer necessary and has been deleated. Rob Link to comment Share on other sites More sharing options...
Colin Mill Posted July 23, 2009 Share Posted July 23, 2009 Rob - In the system as Ford have it do they put the regulator so far from the engine bay as is proposed in this installation? If so then fine. If not then 5 minutes with a calculator is all it would take to check if there is a potential effect. Edited by - Colin Mill on 23 Jul 2009 19:31:04 Link to comment Share on other sites More sharing options...
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