I have had the Walbro upgraded fuel pump in the car for a few years now and it seems to have lost some of its power. It idles at 58 or 59 and when on the spray it will drop to close to 50psi. and only go to about 53 during the run. Is this normal? And what is the least psi to be safe? I am running a 100 shot but may want to go to a 150. Any suggestions? Thanks

 

I wish I remembered what mine used to do before I put the stand alone in the car...

What does your fuel system setup look like...

 

Spraying a 125-hp dry shot (550 rwhp), my Racetronix pump maintains an average pressure near 54 psi at WOT. As can be seen in the attached chart, fuel pressure is not constant. Injector activity causes large pressure pulsations. The stock F-body fuel system is poorly regulated. I have some 97 Corvette fuel rails and plan to eventually switch to a full-return system which should reduce the amplitude of the pressure spikes.