car is 87 turbo II with jdm engine . Which way do the Fuel lines go. Does it go from fuel filter to top fuel rail closet to firewall or go from fuel filter to bottom fuel rail towards front of car. I think I might have had the mixed up? Thanks Marshall

 

Some of the JDM engines had the fuel flow reversed through the rails for some reason. In the USDM cars, fuel enters the lower fuel rail at the back fitting, then goes out and up to the top rail through the front fittings, then goes to the back of the top rail where the fuel pressure regulator is.

In some of the JDM engines the FPD is on the top rail and the FPR is on the bottom, and fuel flow is reversed.

Really it doesn't matter which way you do it as long as the FPR is the last link in the pressurized side before fuel returns to the tank. The front fuel line coming from the fuel filter on the frame rail is your high pressure feed and needs to flow through the rails first, then to the FPR, then out and through the drain tube which is on the firewall under the brake booster.

 

jap s4 turbo engines have the reg on the primary rail and the dampner on the secondary rail

s5 turbo jap engine is the other way around