Nissan 370Z Forum - Not a 370z, but... VQ35HR ST (VSR) Begins

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Quote:

Originally Posted by mad_jelly (Post 3274323)

Got the new line! Thanks Phunk! The existing male AN fitting is too short for the new line.

That doesnt make sense, the length specs on all that stuff never changed... the hose should have been cut to 7.5". Did I cut it too short?

Quote:

Originally Posted by mad_jelly (Post 3274323)

Car still makes 0 pressure when I provide the pump power. Turning over the car still takes 3 or 4 tries with some gas.

Car no longer stumbles when it goes from vacuum into boost but does go way lean as the boost pressure increases. Car is waiting to lean out and go BOOM.

Once the car idles, the fuel pressure registers 45psi. Don't know if it goes up or down when the car goes into boost. Revving the motor in the driveway doesn't put the car into boost. Any tips on motoring the pressure gauge in the engine bay while driving???

If that hose coming off was the reason for the issues, than putting back on alone wouldnt solve the problem. All that hose does is allow the module to siphon fuel from the drivers side. But the siphon needs return fuel pressure to work... so if starvation made it stop running, it would need fuel added to run again even after the hose was connected in order to build pressure and activate the siphon.

That said, if the car is running and making pressure now, its something else anyway. Its most likely a bad pressure regulator or an internal pressure leak in the fuel pump module (missing oring on regulator delete fitting, cracked housing, bad seal between pump output barb and filter housing inlet), or a bad fuel pump.

The hose isn't too short, I believe its an AN union. The threading on the union is too short and does not bottom out the female end of the new hose.

But you're absolutely correct, it has to be something else. The problem still persists. The shop that installed the fuel pump hasn't been known to do a good job so I wouldn't be surprised if it was a cracked housing, missing o-ring, or something stupid.

Regardless, I am inclined to just replace everything. What is the model of the aeromotive fpr? Walbro still the pump to use? I'll start with the big stuff and work my way down.

There must just be a burr on the thread or something, its all compatible stuff, it will fit.

Aeromotive 13109 regulator, Walbro 255 pump (gss342) is good for up to 500-550rwhp depending on many other things. Or you can use an Aeromotive 11142 which is the largest I would recommend for that fuel pump housing.

Before any of it, I would pressure test the fuel pump module but applying roughly 60-75psi of air pressure into the fuel pump module outlet, and this would allow you to check for leaks around the regulator delete or the fuel pump output barb, or cracked housing etc.

Ended up being a ripped O-ring in the regulator bypass, now the car runs rich.

Quote:

Originally Posted by mad_jelly (Post 3295967)

Ended up being a ripped O-ring in the regulator bypass, now the car runs rich.

Was it the smaller or larger o-ring?

Wow great stuff man thnx for posting.

Quote:

Originally Posted by phunk (Post 3296060)

Was it the smaller or larger o-ring?

both :(