Fuel pressure at rail?

chadder1313

Registered User
I just finished installing the new injectors and went to test them before i went any further. I hooked the fuel pressure gauge to the rail and turned the ignition on and the FP will go up to about 45psi then it will drop to about 20psi or so. There is no leaks and the car is apart so i havent ran it. Is this normal?
 
did you jump the fuel pump relay so it is always running? If not the pump will run for a few seconds then shut off.
 
No i didnt jump the fuel pump relay. Just turned on the ignition. I really just wanted to check for leaks. Chris it takes about 10-15 seconds before she gets to about 20psi or so.
 
Your pump is kicking out causing it to drop. You can either jump the realy or ground the eec test connector if you need to adjust the fuel pressure.
 
If you just turned the switch to the run position {on} and dont start the car the fuel pump will only run for a few seconds. The pump will continue to run only if the car is started and remains running. The car should maintain fuel pressure in the rail for quite awhile unless the injectors are leaking down or the check valve in the tank is bad or missing.
 
All i wanted to do is check and see if there were any leaks before i finish bolting everything down. I did not see any leaks around the injectors or regulator. So i am assuming everything is fine. My thoughts were that the rail should hold the pressure from just turning the switch on. I guess my question is with out the pump running should the rail still hold pressure or will it slowly decrease in pressure.
 
The short answer is yes it should if all things are perfect it should hold pressure for hours.Fuel injectors get worn or dirty and leak pressure into the engine and check valves go bad or removed for pump upgrade allowing fuel pressure to return to the tank. As long as the car starts and runs like it should I wouldnt worry too much about it.
 
Ground this port to keep the fuel pump running with ignition on motor off.



fuel%20pump%20test.gif



David
 
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