Fuel Pressure Issue

mark4g63t · 08-12-2014

Whenever I get on it, it goes super lean (confirmed by wideband and feel/ sound of car)

I believe the problem is the Fuel pressure regulator because when I turn the adj. screw on the top it will lower just fine, but only raise to about ~38psi before it stops rising while still turning the screw in (I could bottom the screw out without it going past 38psi).
Other hypothesis is the fuel pump and or the rewire, because the fuel pressure would adjust just fine before fixing the fuel leak and doing the rewire.

I did check the fuel filter and it wasn't clogged or dirty, but I will be ordering a new one since I don't know this ones past.

Anyone know if this is a sign of a bad afpr? or fuel pump?

**asshanson** · 08-13-2014

Where was the fuel leak? At the sending unit to tank seal?
Possibilities for pressure not rising above 38 at idle could be a leak in the feed line inside the tank bleeding off all the fuel above 38psi, or a bad regulator. I had a bad line bleeding off pressure inside the tank before, but on a different car. Even a bad pump should he able to make more than 38psi at idle.

mark4g63t · 08-13-2014

Fuel leak was at the rubber seal between the top of tank and the sending unit where the big white lock ring would sit. While fixing that I created a leak at the fitting for the fuel line and had to get one welded on.

From there I went full braided line from the tank to a fuelab filter (10 micron) then to the rail.

I do remember the pump sitting a little strange like it wasn't fully seated into the rubber o-ring thats on top of the pump between it and the sender but IIRC it was like this before.

Fuel pump is seeing ~13.4V after rewire.

Will check it out and make sure.

Thanks

mark4g63t · 08-13-2014

Here's how the pump sits

mark4g63t · 08-13-2014

Problem solved!
Thanks Asshanson.
Problem was the pump not fully seated in the sender.

**asshanson** · 08-14-2014

Glad you got it fixed.