Hello everyone, i have a disturbing problem


Car is 99 Si
B16a Engine
Stock fuel pump
Aeromotive fpr / marshall guage

I was looking at my fuel pressure, bolted on my aeromotive.
It read about 38 psi with vaccum line attacked and
42psi with it removed.

I try to adjust the pressure past 42psi and it wont budge, it might even go below 42psi by adjusting the regulator.

Does this mean my pump is weak?

 

12 views no post?

 

Fuel pressure should be around 28-36 psi and 38-46 psi with vac. hose disconnected, sounds like you are within parameters. 94

 

also when i prime the pump, the guage drops to 0 very quickly

and car off it drops to 0 in some seconds


but from vac connected then disconnected its only a 2psi change, it should be at about 10psi jump

 

could be a faulty regulator, or as you say fuel pump, but if the fuel pump is having such problems on keeping pressure up at idle ; then it would have a great impact on drivability.
pressure dropping so fast could be a faulty regulator or the usual pump valve

you can amp test the pump to see how much is using

 

How do i test the pump?

do the aeromotive regulators go bad?

 

as said before you can check to see how many amps the fuel pump is using, a worn pump will use more amps to run to produce the same pressure. you can actually put a lab scope on the pump leads and watch the graph and you can actually see the waves moving adversley, showing warn pump.

sounds like the regulator is bad.

crimp the return line, turn the key on,and see what the pressure does now, if it stays up it is a faulty regulator if it drops fast then the pump is bad.

cheers.

 

pinched the return line, and pressure rise

this means the pump is weak?

 

regulator is bad...it's allowing more fuel into the return line than it should.

Go back to stock.

Once you have pressure in the rail, it shouldn't drop unless the injectors are leaking(most likely not), or the FPR is letting fuel by....

 

what about the fuel filter
could this be a factor?

 

what is the pump valve?

 

Ok guys thanks for the info

It was the Fuel Pump