Recently having going through an Walbro pump install, I noticed the following.

Fuel pressure was all over the place. high one time and low the next.
At idle. Best it was about 5-10psi osciallation. I have a Nismo FPR, so I thought it may be the culprit so I swapped to the stock one, same problem.

Ended up the fuel pump was seeing between 5v-10v, most of the time it was 5v..... There is a lot of discussion about rewiring the fuel pump (I did that in my old Infiniti G20 I had), but this time I noticed that the ground was bad and not the power lead. So I regrounded the fuel pump ground to the body, and viola my fuel pressure stabilized and so did the voltage at the pump.

I thought I would put this up as an FYI for people that might have issues in the future.

 

nice find there! Def should be in anyone's diagnose list to check!

 

Thanks for the infos. I'll re-ground the Wallbro preventively.

 

Noob question, where did you ground the fuel pump to? On my 5th gen the fuel pump is in a plastic container with the fuel filter sitting over it so I don't see how I can ground it?

Also, were you just checking the voltage through the fuel pump fuse or where exactly?

Thanks, I just installed a walbro and 440cc injectors and I haven't tuned or installed my T/C yet but at WOT the car sputters and hesitates a little and I want to rule out the fuel pump.