I have a jdm s4, the FPD is on the upper rail and the pressure regulator is on the lower rail. Does the fuel flow into the upper rail and out the lower rail on jdm engines?

 

on all turbo rotaries s4 and s5 the pulsation dampener is on the primary (lower) rail and the pressure regulator is on the secondary (upper) rail. i've had us spec and jspec engines and i know this for a fact. the fuel flows from the filter into the primary rail then to the secondary rail through the pressure reg. then returns to the tank.

 

ok, so the FPD which is suppose to be on the bottom rail, theres also no screw in the bottom one. THe upper rail, which "should" have the pressure regulator has no nipple for a vac line, and theres a screw in the center of it....

 

if it's like you describe it sounds like someone has changed it around. it is supposed to be like i described before.

 

Yes, JDM engines have their fuel rails reverse flow, so the PD's and FPD's are reversed.


-Ted

 

i have a jdm engine and it wasn't like that

 

so, Reted, I can just hook it up opposite, fuel into the upper rail, and out the lower?

Thanks, Tony

 

if his engine, an s4, is like that and mine, an s5, is like the normal us engines, what's the deal then? you can unbolt the s4 FPR and PD but on s5s it's all welded in.

 

so if you wanna run yours like it is just run it to the 2nd rail then to the primary out through the FPR. the FPR must be the last thing in line before it goes back to the tank.

 

Yes, you just need to flip the fuel hoses around.


-Ted

 

whered you get this JDM engine

 

Unfortunately this is not a fact. Most (but not all) J-spec 13BT's have the PD and FPR in opposite locations to US-spec engines.

 

i got my engine from spd racing in san diego, ca