Car struggles to make fuel pressure

jwick · 08-18-2015, 10:20 AM

Quote:

Originally Posted by Mitco39

Going to take it to the track tomorrow night and see what she can do now that I can bump up the boost without going lean again.

im either going to come back with a good trap speed, or a popped engine. lol

You have the replacement standing by or you still contemplating the build?

phunk · 08-18-2015, 01:24 PM

Quote:

Originally Posted by Mitco39

Got it figured, the regulator delete was leaking, but only at about 40+psi. We swapped out the oring and so far so good. I did notice that when clamping down the regulator I could push it down and bottom it out, which leads me to believe that the spacer used above that oring could be a tad bit thicker to squeeze that oring in there a bit better.

If it starts to leak again then ill probably get a shim to put in there to squeeze that oring in its housing.

Thanks for the info Charles, you were bang on, now the car feels quick again. Has no issues holding 70PSI.

If possible I would like to get as much information on why it was leaking as possible so that I can determine if the part should be updated of it it was just a basic o-ring problem. We do have lots of them out there but that doesnt mean there isnt potential for slight inconsistencies in manufacturing of either our component or the factory housing that it secures to.

Do you believe it was the bottom o-ring that was leaking, which is the one we supply that gets squeezed when you tighten the 2 small bolts? This I believe would be the one most prone to a leak of the 2 o-rings. The factory o-ring and spacer reused from the factory regulator which seal on the sides rather than vertical will be less susceptible to leaks.

Please feel free to post or PM me any information or if you think a change to the part would have made the difference let me know.

Mitco39 · 08-18-2015, 02:11 PM

Awesome Charles. Here is some more info..

When I pressurized the feed line it was good until about 40PSI then I started to hear air seeping by what seemed like the back side (side closed to the can) of that regulator. When I took it apart it appears that there is a almost like a keyway in the back side where that regulator slides in. That is where it appeared to be leaking by the upper oring.

I replaced that oring (which I felt was a bit soft, maybe the fuel additives I am using was eating it?) with a new one and she easily held 50-60psi. When putting the clamp back on I was able to bottom out the regulator on its mating surface, which to me implies that there is not very much overall clamping force being applied to that oring to being with. I felt if that stock shim that we use was just a tad bit thicker this would put more pressure on that oring and create a better seal.

Time will tell if I blow that seal out again, I am probably running a higher fuel psi than most guys I would imagine. The regulator is set to 58PSI with the boost reference hooked up to boost only. If I do pop it I will see about getting a shim to fit in there.

Thanks!

Mitch

phunk · 08-18-2015, 05:18 PM

The keyway you describe is where fuel bleeds from the filter housing to the inlet of the regulator.

The regulator delete fitting crushes the smaller lower oring when its seated and tightened down. But it is not supposed to crush the larger top oring vertically. That oring seals by the pressure applied to its sidewalls between the housing and the delete fitting, which is also how it sealed to the factory regulator.

I am surprised it was your upper oring that was leaking. An upper oring leak would allow pressure to leak externally. A lower oring leak would allow pressure to leak into the return channels.

So to clarify, you replaced the factory o-ring and the problem was solved, and kept the same o-ring that we supplied?

Mitco39 · 08-19-2015, 09:51 AM

Makes sense, this lower oring then could stand to be just a tad bit thicker (mind you its probably just squished down from being installed for a year already. In which case there is not much you could do anyways.

The upper oring seemed soft to me, I replaced it with a new one that felt more rigid but yes it was the exact same one. If I had one just a touch bigger I probably would have used that one, but the next size up was much to big to work.

I dunno Charles, I think mine was probably just a fluke and the fact that I am running north of 70psi at times might just be to much for the system to hold. Do you suggest I turn it down and retune?

Also I noticed that the regulator pressure drops about 4psi when it heats up. Aeromotive says to set the regulator cold, is that what you suggest? Just seems like a pretty good drop when it heats up. Also many of the tuning books I have say to connect the 1:1 line to a vac/boost source, I currently have mine connected to a boost only. Should I switch it? I would assume you said a boost only source on this particular car because of the vvel messing with the idle and thus the vacuum around idle.

Mitco39 · 04-06-2016, 10:02 PM

Back to having issues while on the dyno.. I just cant win with this mess.

Ive checked everything, while cold the system is fine, as it heats up the pressure drops to levels that cause lean conditions under WOT. I have started looking to see what the GTR guys are doing.

Something has to be wrong with my intank setup, I mean no one else has any issues at all. Charles, would you entertain me purchasing a new basket with all the mods done by you so that would rule out anything wrong with my intank setup.

I checked my leak down pressure and the car has no issues holding pressure after the pump is unplugged now, which rules out internal leaks I would think. I did hit ~500rwhp on the dyno before the car started to act up.

so that is a plus but had to stop afterwords because she started really leaning out.

Ughhhh.

phunk · 04-06-2016, 10:32 PM

Try doing my level 2 fuel pump modifications which bypass the internal filter entirely. This would eliminate potential leaks at the o-rings or backed up internal filter. This will require adding an external filter inline somewhere though.

Mitco39 · 04-06-2016, 10:43 PM

Quote:

Originally Posted by phunk

Try bypassing your internal filter. Ditch the 180 bend and go straight up and out. See if that solves your problem. If so, its either clogged filter or still leaking at the o-rings. You can add a good external filter under the car if needed. Dont run it very long without a filter, its not an approved configuration for the injectors health... but should be fine for a test.

It could very well still be leaking at the orings, everytime I pull it apart I find what I assume to be oring rubber in the basket. Maybe I am just asking for to much pressure and when it gets hot and the orings get soft it blows them out.

Hard part is in order to bypass that filter I will have to cut that factory line and replace it with fuel hose which means going back to the stock configuration could be an issue.

Would you entertain the idea of building me a basket with the required mods?

instroke · 04-06-2016, 11:36 PM

Quote:

Originally Posted by Mitco39

Back to having issues while on the dyno.. I just cant win with this mess.

Ive checked everything, while cold the system is fine, as it heats up the pressure drops to levels that cause lean conditions under WOT. I have started looking to see what the GTR guys are doing.

Something has to be wrong with my intank setup, I mean no one else has any issues at all. Charles, would you entertain me purchasing a new basket with all the mods done by you so that would rule out anything wrong with my intank setup.

I checked my leak down pressure and the car has no issues holding pressure after the pump is unplugged now, which rules out internal leaks I would think. I did hit ~500rwhp on the dyno before the car started to act up.

so that is a plus but had to stop afterwords because she started really leaning out.

Ughhhh.

Mitch.. I mean no one else has any issues at all. WHAT..!

I am trying to work somethings out myself too, I believe it's part of being a Z owner, I only wish I had taking Auto 20/30 in high school. And I am kicking myself for it now. Hang in there Mitch - but have you considered Zat Zuma's Dual Fuel pump for sale? I think he still might have it. Hope you work it out.

Mitco39 · 04-07-2016, 12:30 AM

What issues are you having? Same thing?

Mitco39 · 04-07-2016, 11:28 AM

Just bought a whole basket and I am going to put my engineering degree to use and try and modify my current one to see what I can come up with lol. (I am sure anyone who works with an engineer will be rolling their eye nows, haha)

I will either wreck it or fix my issue. Ill grab some pictures of what I come up with. Now that I have another basket on the way I am not scared to modify mine past repair.

Hotrodz · 04-07-2016, 12:55 PM

Hey man if you are looking for a solution, I have a Fast Intentions Fast 500 system that was made to resolve that issue. PM me if you are interested.

Sent from my SM-N910P using Tapatalk

phunk · 04-07-2016, 01:31 PM

Quote:

Originally Posted by Mitco39

It could very well still be leaking at the orings, everytime I pull it apart I find what I assume to be oring rubber in the basket. Maybe I am just asking for to much pressure and when it gets hot and the orings get soft it blows them out.

Hard part is in order to bypass that filter I will have to cut that factory line and replace it with fuel hose which means going back to the stock configuration could be an issue.

Would you entertain the idea of building me a basket with the required mods?

I am not sure what the rubber that gets in the basket is from, but its not the orings. I get that same rubber and the ones that have been sent in to me get it also. The orings are Viton and will not degrade. If you replaced an oring with one of your own, its possible that you didnt use a fuel-safe material.

I would gladly assemble a fuel pump module for you and pressure test it before sending out.

In fact, send me the one you are having a problem with, and I will test it as is and tell you if there is anything wrong with it. Turn around time one day, and I will ship it back no charge. I am interested in seeing this for myself for if there is something wrong with it, it will just be something for me to watch out for and help others with.

Remove the level sensor before shipping it, those are fragile and I of course wont need that here.

phunk · 04-07-2016, 01:33 PM

Quote:

Originally Posted by instroke

Mitch.. I mean no one else has any issues at all. WHAT..!

I am trying to work somethings out myself too, I believe it's part of being a Z owner, I only wish I had taking Auto 20/30 in high school. And I am kicking myself for it now. Hang in there Mitch - but have you considered Zat Zuma's Dual Fuel pump for sale? I think he still might have it. Hope you work it out.

are you also having problems with a fuel pump or fuel pressure?

Mitco39 · 04-07-2016, 02:14 PM

Quote:

Originally Posted by phunk

I am not sure what the rubber that gets in the basket is from, but its not the orings. I get that same rubber and the ones that have been sent in to me get it also. The orings are Viton and will not degrade. If you replaced an oring with one of your own, its possible that you didnt use a fuel-safe material.

I would gladly assemble a fuel pump module for you and pressure test it before sending out.

In fact, send me the one you are having a problem with, and I will test it as is and tell you if there is anything wrong with it. Turn around time one day, and I will ship it back no charge. I am interested in seeing this for myself for if there is something wrong with it, it will just be something for me to watch out for and help others with.

Remove the level sensor before shipping it, those are fragile and I of course wont need that here.

I would take you up on the offer if my car wasn't currently strapped to the dyno. Id love to send it to you but I think I will just try to modify this one myself since I have another one coming in a week or so. I cant imagine I am doing anything wrong as I can apply 50psi of air to the outlet port and she holds, and I can confirm that when I shut off the car it holds fuel pressure with no issues (after fixing that oring). I am going to do what you said and bypass the basket filter and put a inline filter in the car. So it will go straight from the pump through a inline filter and to the engine, then back in through the venturi setup. I am going to try and remove the factory filter from the basket to allow for more fuel to sit in the basket.

I just went out and bought all the parts to do this, if I didn't want my car for the weekend I would have sent you it. If I do this and its still dropping off then my next place to look is the wiring, which could be the issue with the repeated higher pressures that the 1:1 regulator puts the pump under. I am also going to turn down my pressure since I am only hitting ~60% duty on my injectors so far.

Ill take some pictures, and you can see (in horror probably, lol) the mess I am going to make to try and fix these issues haha. If this works then ill have another basket to maybe try and see if I can fit it in the other side and have another pump T into the outlet inside the tank and run 2 pumps (one from each side) in parallel together. This would also act as a transfer I would think. But thats in the future.

I do appreciate all your input Charles, if you dont mind what is your baseline pressure set at?

08-18-2015, 02:11 PM	#48 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 132	Awesome Charles. Here is some more info.. When I pressurized the feed line it was good until about 40PSI then I started to hear air seeping by what seemed like the back side (side closed to the can) of that regulator. When I took it apart it appears that there is a almost like a keyway in the back side where that regulator slides in. That is where it appeared to be leaking by the upper oring. I replaced that oring (which I felt was a bit soft, maybe the fuel additives I am using was eating it?) with a new one and she easily held 50-60psi. When putting the clamp back on I was able to bottom out the regulator on its mating surface, which to me implies that there is not very much overall clamping force being applied to that oring to being with. I felt if that stock shim that we use was just a tad bit thicker this would put more pressure on that oring and create a better seal. Time will tell if I blow that seal out again, I am probably running a higher fuel psi than most guys I would imagine. The regulator is set to 58PSI with the boost reference hooked up to boost only. If I do pop it I will see about getting a shim to fit in there. Thanks! Mitch __________________ 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

08-18-2015, 05:18 PM	#49 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,668 Drives: 370 Rep Power: 974723	The keyway you describe is where fuel bleeds from the filter housing to the inlet of the regulator. The regulator delete fitting crushes the smaller lower oring when its seated and tightened down. But it is not supposed to crush the larger top oring vertically. That oring seals by the pressure applied to its sidewalls between the housing and the delete fitting, which is also how it sealed to the factory regulator. I am surprised it was your upper oring that was leaking. An upper oring leak would allow pressure to leak externally. A lower oring leak would allow pressure to leak into the return channels. So to clarify, you replaced the factory o-ring and the problem was solved, and kept the same o-ring that we supplied? __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph

08-19-2015, 09:51 AM	#50 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 132	Makes sense, this lower oring then could stand to be just a tad bit thicker (mind you its probably just squished down from being installed for a year already. In which case there is not much you could do anyways. The upper oring seemed soft to me, I replaced it with a new one that felt more rigid but yes it was the exact same one. If I had one just a touch bigger I probably would have used that one, but the next size up was much to big to work. I dunno Charles, I think mine was probably just a fluke and the fact that I am running north of 70psi at times might just be to much for the system to hold. Do you suggest I turn it down and retune? Also I noticed that the regulator pressure drops about 4psi when it heats up. Aeromotive says to set the regulator cold, is that what you suggest? Just seems like a pretty good drop when it heats up. Also many of the tuning books I have say to connect the 1:1 line to a vac/boost source, I currently have mine connected to a boost only. Should I switch it? I would assume you said a boost only source on this particular car because of the vvel messing with the idle and thus the vacuum around idle. __________________ 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

04-06-2016, 10:02 PM	#51 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 132	Back to having issues while on the dyno.. I just cant win with this mess. Ive checked everything, while cold the system is fine, as it heats up the pressure drops to levels that cause lean conditions under WOT. I have started looking to see what the GTR guys are doing. Something has to be wrong with my intank setup, I mean no one else has any issues at all. Charles, would you entertain me purchasing a new basket with all the mods done by you so that would rule out anything wrong with my intank setup. I checked my leak down pressure and the car has no issues holding pressure after the pump is unplugged now, which rules out internal leaks I would think. I did hit ~500rwhp on the dyno before the car started to act up. so that is a plus but had to stop afterwords because she started really leaning out. Ughhhh. __________________ 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

04-06-2016, 10:32 PM	#52 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,668 Drives: 370 Rep Power: 974723	Try doing my level 2 fuel pump modifications which bypass the internal filter entirely. This would eliminate potential leaks at the o-rings or backed up internal filter. This will require adding an external filter inline somewhere though. Mitco39 likes this. __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph Last edited by phunk; 04-06-2016 at 10:34 PM.

04-07-2016, 12:30 AM	#55 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 132	What issues are you having? Same thing? __________________ 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

04-07-2016, 11:28 AM	#56 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 132	Just bought a whole basket and I am going to put my engineering degree to use and try and modify my current one to see what I can come up with lol. (I am sure anyone who works with an engineer will be rolling their eye nows, haha) I will either wreck it or fix my issue. Ill grab some pictures of what I come up with. Now that I have another basket on the way I am not scared to modify mine past repair. GaleForce likes this. __________________ 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

04-07-2016, 12:55 PM	#57 (permalink)
Hotrodz A True Z Fanatic Join Date: Aug 2012 Location: NW, AZ Posts: 9,330 Drives: 10 Nissan 370z Nismo Rep Power: 2684385	Hey man if you are looking for a solution, I have a Fast Intentions Fast 500 system that was made to resolve that issue. PM me if you are interested. Sent from my SM-N910P using Tapatalk __________________ *Fast Intentions TT Installed and Tuned by Seb at SpecialtyZ 610whp 560tq:\|Fast Intentions 3" TT-TDX*\|SpecialtyZ/Fast Intentions 72 Row Oil Cooler\|SZ 6 Puck Clutch & Flywheel\|3GsCustoms\|Z1\|Wavetrac\|Hotchkis\|Whiteline \|Blitz\|Fortune Auto 500\|Fujimura\|SPL\|H&R\|TK\|TWM\|RPM Rollbar\|Sparco\|Next Level Performance\|TrackSpec\|AeroFlow Dynamics\|Pioneer\|

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