Not a 370z, but... VQ35HR ST (VSR) Begins

phunk

OR perhaps consider the HR S1-S or S2 kits that will be released next week featuring our new HR billet rails

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tturbo370z

Those looks super sexy Mr Phunk

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JUST STUFF 800whp700wtq

Tturbo370z 800whp build
https://instagram.com/jdm_370z

mad_jelly

I believe the shop already ordered these. They told me they ordered them Friday of last week.

mad_jelly

Haven't been back to the shop to hear it. Car still needs rails and mafs and tune.

phunk

OH its those guys, I know who youre talking about. They ordered them before I even had them back from anodizing. I got 3 sets back yesterday in blue, and have some in black coming next week.

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mad_jelly

blue, black, pink... doesn't matter to me. Just as long as it works.

EVOHUNTER

You couldn't have said it any better, I do all my own stuff. You want things done properly or to your likings, do it yourself. I know a lot of people don't have the resources, tools or just aren't mechanically inclined. But it really helps when trouble shooting.

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mad_jelly

Car is back!

The wait was well worth it!

The idling issue seems to be gone.
Car sounds great, the TDX exhaust is louder at idle but quieter while in boost (mostly due to the recir). I can hear the turbo spin and the bov much clearer now!
Car doesn't break up past 5k
Car doesn't smell like gasoline

New MAF, fuel return, properly gapped plugs, fixing the boost leaks, new tune, and 3.5" CAT yielded another 30whp and 40 ft-lb on 8lbs. @13lbs, it yielded another 20whp and 60 ft-lb.

I'll try and upload a video/sound clip. The TDX exhaust does sound very different from any other VQ exhaust.

mad_jelly

300 miles later

Car won't make any fuel pressure when I put the car in ACC. Only after cranking the car a few times will the car reluctantly start. This of course happened on my way down to a wedding. (I made it... thankfully)

Anyways the exhibited behavior happened right after driving 2 hours, then stopped for food. Tried to get back on the road and the car just wouldn't turn over. Finally got the car to turn over, however whenever the car got anywhere close to boost, the car would go full lean and stumble hard. Limped the car another 2 hours and had to drive it under 2k rpm to make it to the wedding.

I believe it to be a fuel issue. But not 100% sure if it was the fuel pressure regulator, fuel pump, or a kink somewhere. Im leaning towards fuel pump buts really a guess. Fuel pressure will hit 45psi once the car turns over. Im thinking the vacuum must be pulling the diagram open enough to get fuel through to keep the car going. However, once the boost kicks in, the pump must not be able to put enough pressure through the lines.

Anyways, took the pump out and this is what I found.






Return feed got loose, bunch of crap all over the collector? I don't think these things would cause the problem so any help would be appreciated.

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phunk

I dont know what all the black stuff is in the bottom there.

But, that hose coming off could cause the car to not be able to run in a way of fuel starvation.

With that hose not connected, the over-tank venturi will not function and the module cannot recover fuel from the driver side of the tank. This would cause the car to have fuel starvation issues somewhere around 1/2 tank on the gauge. (Hard to predict where exactly on the gauge as fuel can slosh back and forth in the tank, but ultimately if there is little-to-no fuel on the passenger side, the car is going to starve)

PM me your address and I will drop you a new hose for that in the mail tomorrow since that one is looking pretty unhappy.

If your tank has plenty of fuel on the passenger side and it still wont run, there is more diagnosing to do.

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phunk

If you havent run into it yet, there is a pretty recent PDF I put together that goes over the 350z fuel pump module: http://host.cj-motorsports.com/pdf/3...uel%20Pump.pdf

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phunk

BTW if you want to test the theory immediately, you can put it back in even with that hose still off, and add 2 gallons of fuel to the tank... when you add fuel it will land on the passenger side by the pump. If the car starts up like everything is normal, than you know its fuel starvation from that hose coming off.

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mad_jelly

The car had plenty of fuel

Im not sure of the black stuff either...

My form of diagnosing is tearing things apart and replacing parts until things magically work? Unfortunately I don't have the experience to say its one part or the other.

Is there an fuel pump independent way of determining if the regulator is functioning properly?

Call me a noob, but my thought process was to 1) put everything back together, 2) disconnect the vacuum hose on the fuel regulator and hook it up to a hand pump. 3) Supply power to the pump and use the hand pump to draw the diagram up and or down and watch the fuel pressure. The assumption here is that the fuel pressure regulator is a binary device in that it either completely works or not.

In any case, if im going to replace this fuel pump, is there anything else out there that may be more reliable/better than the Walbro GS342 I have in right now?

Dcocci

Plug the hose back in and tighten it. Go from there. If you are having fuel pressure problems, and a hose is loose in the fuel system, then that's probably the problem.

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-08 Porsche Cayman S

mad_jelly

Got the new line! Thanks Phunk! The existing male AN fitting is too short for the new line. regardless, reattached the old line. 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???