Car struggles to make fuel pressure

phunk

Ive never seen a regulator react to heat, it would probably take some really extreme heat - they are rather simple devices and if constructed with quality materials they are not very prone to failure without debris making it in. It wouldnt hurt to try swapping the regulator out just to test with another, although its unlikely the problem.

For hose clamps, smallest you can find probably, its a 1/4" ID hose. Thats the return side that blue hose I was looking at. If it leaked the over-tank siphon and canister refill would be weakened.

If there is pressure problems even with a full tank when the car heats up, its probably a bad pump. The pump in your photos is red, Walbro doesnt make any red pumps. If that isnt an Aeromotive Stealth pump its an ebay pump that probably needs to be replaced.

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Mitco39

Charles,

I dont have another regulator to test at the moment but I dont think it would be that either if its unheard of.

Would you clamp the supply side black tubes as well? I noticed there is no clamps on them, can they leak? Should I upgrade them now that im pushing ~70PSi at times?

The pump is not Aeromotive, I bought a Aeromotive 340 and am going to be installing here once i burn some fuel out of my tank. Had a vendor account and could get it locally so that worked out nicely. Just dont want to have issues with our trip down the vegas next week.

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2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
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phunk

The factory black tubes dont need any clamps. They are either Nylon or PTFE and press fit very tightly on their barbs.

I bet that fuel pump will solve your problems. Just watch for a possibly idle pressure spike unless you already opened up the swirl jet orifice enough to accomodate that large of a pump.

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Mitco39

Ok I wont worry about them then, thank you.

Should the regulator along with the pressure dampener be sufficient with these spikes? Ill have it apart anyways I can always drill it out with the link you provided me earlier. Im not to concerned about a bit of a fluctuating idle the car does it right now anyways.

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

phunk

Its unrelated to the regulator and dampers. You can read about it here: CJM: Ultimate 370z Fuel Pump Thread

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Mitco39

I see so its actually on the return side of things coming back to the tank after it passes through the regulator? Makes sense I will drill it out as per that thread.

Thank you sir.

Mitch

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

Mitco39

So after changing the pump I had a close look at my wiring and it appears to have gotten pretty hot which I think was what was causing my issues all along. That said I am going to run some 10-12GA back from the battery today. However I am still not happy with how it has to drop down to some ~22ga to get through that plug, I think this is very insufficient as according to the pump spec sheet I can expect a constant draw of about 16-18 Amps.

Has anyone every modified the top housing to run the 10-12GA directly into the fuel tank? I want to try and bypass that plug all together if possible.

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

Mitco39

Something like this would work but our car needs 5 pins for the bulkhead.

Racetronix - Fuel Pump Wiring Kit MP150/280, Generic - Kit Configuration Page

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

phunk

With the aeromotive pump I was overheating the wiring due to bad connections at the terminals, I redid them all and soldiered them and havent had any trouble. Since the top is plastic, you dont have to do anything fancy to get larger wires through to your pump, you can just run a hex screw through the top and use them as power/ground lugs. The connector you linked would need some sort of bung to insert it into.

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Mitco39

I thought of that, the only concern I have is I have to find copper bolts to keep the conductivity up otherwise the bolts will get hot and melt the housing and make a mess. Did you end up going through your housing like this Charles? I just have a 1600 mile road trip coming up next week and don't want to introduce any issues.

Thank you sir

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

phunk

Nope I am still using the stock plug and stock wiring. Just upgraded the wiring inside the tank and soldiered up the terminal to reduce hot spots.

The stock wiring back to the tank gets really hot and I am surprised it never blew a fuse. If it were a customers car, I would have put in a relay kit.

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Mitco39

Stock wiring? wow. I ran 10Ga back to the tank yesterday and got it to the point where it gets warm to the touch but it is no longer hot. I attribute that to soldering my connections instead of using splices as I imagine the internal resistance of a buttsplice is significantly higher and thus got hot.

That said after the car warmed up the idle fuel pressure dropped again. I was doing some reading and have read that fuel pressure gauges can easily be affected by heat and that this is normal. I do know that regulator gets hot to the touch when the car is driving around.

For example the fuel pressure when cold sits 58-60PSI, hot at idle it sits around 55-57psi. I am going to do some more research when I get time this morning to see if thats normal and if it is a possibility that its the heat affecting the sensor.

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

Mitco39

Just got to Vegas, fuel pressure was fine till the temps got up to about 210-220F and the idle fuel pressure dropped down to 40-50PSI and I could confirm that it was low because my AFRs were showing leaner than it was when it was at 58PSI.

I am really starting to think this regulator is being affected by heat and that spring that regulates pressure is getting weaker with the heat.

Possible?

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

instroke

Stay outta high boost, have a good time in Vegas! And a safe trip back.

phunk

Never heard of it happening before but I suppose anything is possible. I'd still bet on the mystery brand pump. Unfortunately its unlikely to be diagnosed fully until you begin the process of elimination.

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