I wanted to find out how much the stock fuel pumps can handle. I have a 04 cayenne turbo with 61000 miles and have done a few mods with an evom tune and I have been having issues with it pulling timing at WOT. I had some readings pulled on runs from durametric and it is showing really high injection timings which the EVOM tuners said is likely a fuel delivery issue. I am not having any issues with normal driving or idle, but could the pumps be having problems at high engine loads to keep up and this is how it is presenting itself. I saw that the part numbers for the OEM pumps have changed over time. Are the new ones better or upgraded? I would appreciate your thoughts on what I am experiencing. I though of having the fuel pressure tested or maybe I will just change both fuel pumps to see what happens. FYI, I have already changed the fuel filter.
Thanks,
Martin

 

Its possible that only one of your pumps are bad or the filter is getting clogged. There is a procedure for pulling the fuel pump fuse and testing.

I had both my pumps replaced at about 90k and unknown to me one of them was fried and the vehicle still ran just fine until the other one died and the car just quit.

If I remember right you can pull the fuse for the pump and the computer should activate the secondary pump. I would just google it.