why is fuel pressure dropping?
04-10-2011, 11:36 PM
#1
why is fuel pressure dropping? i swapped in a racetronics 255 and their hotwire kit. i am a full bolt-on ls1 with cam, heads, P1SC procharger, etc. about 1/2 throttle my guage drops from 62 to 55 psi. i know at 1/2 throttle i can not be overloading the pump. with my setup i can probably be around 550-600 horsepower so i know i need another pump. however, if i am running lean and dropping fuel pressure just by punching the gas then something has to be wrong. btw, i have stock fuel lines and fuel rails. a new fuel filter is on the car as well. any suggestions???
04-11-2011, 07:02 PM
#2
The regulator may be controlling at a lower pressure (55) which is generally OK if tuned for that pressure.
I have seen most 255's have 62 at idle which is a function of the pump overloading the stock regulator. In this case the pressure will drop as you increase load... perfectly normal.
Try to see if it holds at full throttle. This will prove the pump capacity. Peak power fuel pressure will prove the pump capacity.
I have seen most 255's have 62 at idle which is a function of the pump overloading the stock regulator. In this case the pressure will drop as you increase load... perfectly normal.
Try to see if it holds at full throttle. This will prove the pump capacity. Peak power fuel pressure will prove the pump capacity.
04-12-2011, 12:42 AM
#3
i will check that out next weekend. i know my wideband was reading 16:1 at full throttle so i did not want to stay on the gas. i will try to be safe but look at the fuel pressure guage more closely, not just the wideband.
i know the car needs a better tune. i just want to put in another pump before the tune if it needs it to avoid having to tune the car multiple times.
i know the car needs a better tune. i just want to put in another pump before the tune if it needs it to avoid having to tune the car multiple times.
