Ok i have 98 420a ill start with mods



hahn super 16g turbo kit
255 walboro fp
fireball ignition box
hahn fpr
new block bored .20
.20 wiesco pistons and rings 8:1
stage III cams
obx fuel rail and fmu 12:1
apex safc I but i have safc II now just not installed

i pulled je pistons outta the car and they had freaking chips missing off of them so i new it was starved for fuel..i havent put it back together yet until i can figure out my fuel issue... I was wondering how to run the lines off the fuel rail straight to the hahn fpr or fmu or this is where im really confused because theres a line coming off the stock fuel rail thats on right now and it goes straight into the fpr and then a rubber hose goes underneath the car and back to the rear passenger tire and goes into a silver looking thing and then splits off into two...i am gonna take all of this out and redo it..i was wondering how to run every fuel line to be right any additional info will be accepted to lol

The 96'+ models have a "returnless" fuel system. The passengers side of your fuel rail has a schrader vavle.
What I did was remove the valve and make a return fuel line. (Config #1 in the diagram)

Get me pictures....lets figure out whats wrong with yours first so we can make sure we are correcting the issue and not just throwing money at it.

Some of what you are saying sounds correct but the parts under the car are confusing me.

second: We need to test that regulator/FMU to make sure its working correctly. if its not then that is how you ran lean.

What you will need to test the regulator is some type of air compressor and a spare air regulator. The air regulator you can get from any home depot or menards in the air tool section. What you want to do is use air in place of fuel. then slowly apply air pressure through an air regulator into the boost port. You want to try it at 0psi then raise it to 5psi and see how the air pressure changes on the fuel side. Follow me?


Terry

Ok. I should have pics on monday...only i should have mentioned the fmu is brand new in a box so is the aftermarket fuel rail...i havent put them on yet because the engine is out of the car and i have no idea where the fmu goes....but yeah it has hahns black box on there right now until i rip that off monday...so since it didnt have the fmu on there im sure thats why it ran lean then


i just didnt know if the line that runs back and splits into two underneath the car was the fuel return line of if i had to run another one back... my car is a 98 talon so is my setup config 1 or config 2 on that diagram and also if i am doing this myself monday where do i actually bolt that fmu up at

Jerami

If you don't have a fmu and you boosted, then there is your problem right there.


(Ignore the circle)

This is how your fuel filter/fpr and return line should look.
Your stock fpr is the circular thing towards the top, a little towards the left.
The line coming off of that is the "return line". (It's the rubber line towards the top; just in case your confused about the fpr)

You have no return line coming off the rail, that little 6" rubber line that goes to the fuel pump is your return.

The prior picture I posted is how to setup your fmu, you can choose between config. 1 or 2.
You can removed the schrader valve and run a new return fuel line, or you can just put it in the stock 6" return line. (After the fpr, so you would cut that 6" return line)