89bulletlx

Ok my car has been run a lil funny . so i was looking at my fuel pressure and its10 psi with the vac lineonor off the regulator . Is this low or about right.If low would it be the pump or regulator? Is there a way to test fp or fpr ?

Joel5.0

With 10 psi the engine wouldn't even start....... install a test FP gauge to the schrader valve and confirm the FP reading.

89bulletlx

used 2 diff fpg and they both was 10 to 15 psi

nitrous_bob

is it carbed ?

efi needs 35-36 psi at idle

aode08

have the car running,

35 psi stock engine NO MODS

40 psi engine modded lightly,

42-45 psi Head, Cam, Intake, Stock Fuel Pump.

Numbers past 40, makes the ecm use a different strategie and effect the injector's timing to keep the A/F on track within the limits of factory programming.

Depending on your setup, this can make or break you.

If you have a adj reg, have fun and see what fits you best, but dont be suprised if you find a powerfull setting, only to have the ECM fall back on its tables, andif your outside those tables, it WILL do whatever it can to fall back within them.


The A9P and A9L ECM's have better perfomance strategies, than the others, but nothing beats a A/F Guage, and tuning software while on a dyno.

89bulletlx

its efi so i put a new fuel filter on no help.worth a try looks like pump

89bulletlx

set up
1989 Mustang LX 5.0 Edelbrock Performer 5.0 EFI Intake Msd 6AL MSD blaster coil March Performance under drive pullys a/c ELIMINATOR smog ELIMINATOR cam bbk cold air bbk70mm THROTTLE BODY 73mm mass air ford raceing headers and H pipe 40 flowmasters T 5 TREMEC 373 9' ford rear end [/align]

aode08

have the car running when checking

89bulletlx

car is runing but it sounds like its not getting fuel i just dont know if its rhe fpr or fp

89bulletlx

Put fp and fpr on and still only getting 15psi