For some reason on Jason sadler's car, the fuel pressure gauge currently reads 7 psi at idle and 10 psi while moving. What could be causing this? Obviously the car is seeing more than 7psi of fuel pressure if it runs, but what would cause the gauge to read this?

The fuel setup is a stock FPR with a Cartech FMU, and he has a full sweep Autometer fuel pressure gauge. Everything was brand new. Currently the fuel pressure gauge is tapped into the line exiting the fuel rail, right before the FMU. Should we put the sender before the fuel rail?

On my car, we put the sender right after the fuel filter, and it always read accurately. But someone told us it would be fine to tap it right after the rail, so he did it.

 

It should be on the exit line after the Cartech going back to the tank. Most people recommend this spot instead of the supply line.

I told Jason when he called me to put it on the fuel return right before it hits the tank, basically being after the cartech.

Dixit

 

if you have a stock FPR, then you need to have the fuel pressure sending unit before the fuel rail. at ZERO boost, everything before the stock FPR is pressurized, but once the fuel exits the stock FPR the pressure drops significantly - even if you have an FMU after the stock FPR. the only time the pressure sender(between stock FPR and FMU) will see more pressure is when you are in boost(when the FMU kicks in). so basically, you need to have the pressure sender before the stock FPR and the only way you can do that right now is to place it before the fuel rail and after the fuel filter.

 

thank you thomas and thank you dixit.. now i need to figure out my other issues, see other post in this forum.