^thanks for the info .

 

It's too bad that the Evo's fuel rail doesn't feature a built-in Schraeder valve-test port. Most domestic EFI cars have a test port in the fuel rail. It is so easy to just screw on a fuel pressure gauge if there is a test port in the fuel rail.

With a fuel pressure gauge you can monitor fuel pressure at WOT. Usually when a pump starts to go bad, the WOT fuel pressure reading will start to drop off a couple PSI at first, then it becomes progressively worse.

A fuel pressure reading at WOT is the preferred method for monitoring a fuel pump's health. Fuel pressure is a direct reading, whereas AFR readings, although useful, are an extrapolation requiring interpretation.

Lean AFR's can be due to other factors not necessarily related to a weak fuel pump. Also, accurate AFR readings are dependent on the condition of the particular O2 sensor in use. The accuracy of O2 sensors degrades over time. AFR's are an indispensable tuning tool but, IMO, a dedicated fuel pressure gauge is the superior method for monitoring drops in a fuel pump's output, on the fly, at WOT.

 

More fuel pumps die in the summer months than all the rest of the year combined. Fuel pumps are cooled by the fuel in the tank. If you let your tank run low, there's no fuel on the outside of the pump to conduct away the heat. Presto, overheated pump...

 

^^^^^^ Ten-Four^^^^^^^^

 

thank you so much for these helpful info guys. I actually drove the car pretty hard today and it was a cool temp day so no extreme whine from the pump. I am gonna keep a full tank now so heat will not bother the pump. Thanks again.