What goes on inside the infamous FMU???
 

Hey I wanted to know what the FMU does exactly....I know it richens things up but how? I mean how does it trick the ECU into giving up more fuel? Does it alter the map voltage, coolant temp sensor or what? does it have the same drawback as the AFC hack where it advances timing too much in the lower revs? thanks!

Re:What goes on inside the infamous FMU???
 

I thought it was completely mechanical????
Just stored fuel and delivered more flow into the injectors?

Re:What goes on inside the infamous FMU???
 

all it does is limit the amount of fuel that can go back through the fuel return, thus backing up fuel and making the pressure rise

Re:What goes on inside the infamous FMU???
 

I always thought that that was a Rising Rate Regulator....I know what that does. I mean the Black and blue bowes people use from the Greddy kits thanks!

Re:What goes on inside the infamous FMU???
 

boxes not bowes right?..im pretty sure they just change the map signal