when i first start my car (99 firebird, small cam bolt-ons) the fuel pressure goes to 45 then within 5 minutes of running it drops all the way down to 20 then spikes to 30 then down to 15 and so on. i have a walbro 255 that is about a year old. i was told it sounds like a pressure regulator but i also heard about th wiring problem you can have with a aftermarket pump. how do i check the wiring to see if its wires overheating or the regulator? thanks

 

Funny thing, I just discovered today I have this SAME exact problem... My does not pulse, but does drop off to 40 and below at about 4k and up. I to am wondering about the re-wire "hot" kit, and has it worked. I discovered this while on a dyno today when the car consistently went lean. fuel dropped out about that 415 HP mark at 4K.
Anyone, anyone???

 

ordered mine from full throttle speed today

 

Installed the racetronix kit and problem solved. Pressure holds steady all the way through the rpm band now!! What a relief to know I'm not running lean anymore.

 

I went thru 2 walbros in 12 months... Pressure was good then slowly drop, sputter then eventually die on me. I bought the racetronix harness and pump and so far its been good to go.

 

I have gone through 2 racetronix pumps in 2 years and I also have the hot wire kit and a KBB. I have no idea what is causing my fuel pressure to drop. The same thing happens everytime, I put in a new pump and everything is perfect it holds 59psi. then as the months go on it just drops and drops and drops. does anyone have any idea what the heck is going on with my system?

 

stock fuel lines?

 

The rubber hoses on walbros crack and break. I had this happen to me. Could be the problem.