How much range should I get from FPR?

TPI 85 Blazer · Post by **TPI 85 Blazer** » Fri Jun 23, 2006 8:03 pm

With no vacuum on my fuel pressure regulator, I see about 44psi. When I apply about 15 psi of vacuum to the regulator, fuel pressure only drops to 38. Is it a big problem to not have a 1:1 relationship or will this easily tune out (the MS-II is not on the vehicle yet)?

fscott · Post by **fscott** » Sat Jun 24, 2006 2:39 pm

As long as it's consistent, you'll be able to tune around it.

Big Creek · Post by **Big Creek** » Sun Jun 25, 2006 9:37 am

That is a normal drop in pressure.

Todd

TPI 85 Blazer · Post by **TPI 85 Blazer** » Sun Jun 25, 2006 1:21 pm

OK, everything I have read about FPR says that the pressure drop across the injector is supposed to be constant. I guess the only concern then would be if I can't get a steady idle. The injectors arent' oversized.

I don't know why I haven't thought to go measure the pressure on my car, with factory MPFI.