Fuel System 101

[Archbish]

So, I\'ve not my shiny new 1200cc injectors (direct plug into the stock rails), and want to make the 13bt fuel system parallel instead of series. The current system goes:

Tank ->pump ->primary rail -> secondary rail -> return to tank.

I\'d like to change it to



But looking at the fuel setup, there\'s all the vacuums and solenoids and ****e. Given I\'m changing the ECU to Microtech (or similar), and the car harness is a custom jobby, do I need to keep all this crap? I have this daft idea that the fuel system should be a very simple thing, and can\'t figure out what all these damned solenoids are all about!!

[nikp]

Are we talking the FD?

[Archbish]

Nope, the 13bt engine going into the FB...

[Brett]

No - this is for Bish\'s 13BT 1st gen

Can you give us a clue as to the current layout of the fuel system - I can;t recall it off the top of my head...

[Prof]

Bish - you need to change the 2nd Y piece that\'s going back to the tank for a Fuel Pressure Regulator with 2 inlet/outlet ports and a return/feed port. You can get them with or without a pressure gauge - Aeromotive or SARD are good brands.
 
Check the following link for details of the setup:
 
http://www.fc3spro.com/TECH/MODS/FUEL/fsystem.htm
 
You then just need one vac line to the top of the Fuel Pressure Reg.

[Archbish]

Cheers Prof - I\'ve seen that site, and thought it looked pretty simple. But it\'s the pressure sensors (?) at the end of the rails that are confusing me - they seem to shoot off to some solenoid.  What\'s all that about?

[Prof]

Cheers Prof - I\'ve seen that site, and thought it looked pretty simple. But it\'s the pressure sensors (?) at the end of the rails that are confusing me - they seem to shoot off to some solenoid. What\'s all that about?

That\'s the PRC system - it\'s designed to increase fuel pressure during a \'warm start\' to reduce the likelyhood of the fuel percolating and making starting a little unreliable.  I\'m pretty sure you could do without it and just dab the throttle when you start to get the same effect, besides which your parallel system will flow much better, and you\'re doing away with both the pulsation damper and stock pressure regulator which is where that\'s going to happen.
 
You only need the one vac line on that parallel system

[Archbish]

Thanks again Prof!!  I\'m kinda figuring that it I should be able to massively simplify this setup on the FB.  It\'s essentially a closed loop circuit, so as long as the ECU knows the fuel pressure (?) then it should be fine to remove all that stuff, and have a much easier system...  



right?

[Prof]

That\'s my understanding of it - I was thinking about doing this mod myself, but there is actually quite a lot of spare capacity in the stock system once you upgrade the fuel pump and injectors.  The main reason for doing it from my point of view would be simplification/reliability.
 
I actually need to cut some fuel at idle / low rpm on my stock 550\'s because of an increase in fuel pressure with the new pump - but they were good for 317BHP at the fly !