so im finally finishing my FD intake swap and i removed the metal vacuum spyder.my question is, does the fuel line that comes off the fuel filter go into the primary fuel rail or the secondary by the regulator? i have a JDM s5 turbo motor. thanx alot in advance for any info

 

it's not too hard to try. hook everything up except for the fuel return line. that's the one that doesn't come from the filter. just pick a direction...we'll check to see if it is correct. put the return line into a cup. put your ignition switch to on. Now go to the left side (passenger side) strut mount, and there is a two-prong connector right around there. it is a little closer to the front of the car i think and probably hidden. It is a yellow connector with a rubber boot around it. Now with the ignition to on, bridge the two connectors with a wire. this jumps your fuel pump, and if fuel runs out into the cup; the line is hooked up right. if it doesn't, reverse them.

 

Or how about this.......The last item in the system prior to the unused fuel being dumped back into the fuel tank, is the fpr. So it stands to reason that the return line will go where the fpr is, and the feedline will go............yes! Ah, the fpr is the jobber with the small vac hose on it (just in case).

 

Most J-spec engines have the FPR on the primary rail, unlike US motors. The engine won't run if you connect the lines wrong, so to be sure you get it right connect the supply line (from the filter) to the rail with the PD (no vac nipple) and the return line to the rail with the FPR (vac nipple).

 

after beliving what NZ said for a while that they were all reversed. (never touched a j-spec myself) I've since heard that S4 and S5 are different. one is the same, one is reversed. can't remember which way is which.

might clear up the "most"

 

My S4 is reversed.

 

thanx for the info guys