Fuel Pump WTF (part 2)

[ChrisF]

Under light to medium load it remained virtually unchanged....maybe 45psi from 40 at idle tops...the car has no crazy cam in it, I believe it is stock. The car makes about 14-15" of vacuum at idle if I recall....

The fuel pressure only really responds with boost, and it does seem relatively linear.

The regulator is a Kenne Bell billet unit, and seems to be in ok shape. Intersting point though- the line that goes to it has a zip tie on it, and what looks like maybe a little sealant of some sort....maybe the previous owner has problems with it popping off or leaking? It seems to seal up okay now...

I will more closely document the fuel psi at line on/line off condiitions, but I believe these numbers are correct.

Again, nothing else was changed- why would this problem surface now? If anything, I would assume I have more than enough fuel, not a shortage.

 

[Racetronix]

Might be a good idea to purge or replace those lines. All it takes is a small amount of silicon sealant to create problems. Make sure the regulator holds vacuum by testing it with a hand pump. This will tell you if there is a leak in the diaphragm.

Jack
Racetronix

 

[Louie L.]

Im wondering , is you car knocking or showing retard on a scan tool?

 

[ChrisF]

Louie, NO knock at all on T-link until it lays down at 20 psi....

the regulator goes from 40 psi to 60 psi (+20) so it seems linear to boost, which I am told means it's okay.

It also was tested today with a vacuum pump for leaks, and it hold vacuum with a very very slowleakdown (maybe the test tool).

I'm starting to wonder if it's somehow chip related, but the car ran fine until the change, and I don't see how those other items would be affected (chip, maf, etc..)