Fuel pressure regulator on fuel rail and new FPR

Discussion of technical issues and ideas (engine, chassis)

Moderators: P3g4sus, Daniel, rat, Draco, Riekert

Post Reply
User avatar
Speed breeder
0.7 Bar Boost
Posts: 741
Joined: Wed Jun 06, 2007 10:19 pm
Car: S13
Location: Roodepoort

Fuel pressure regulator on fuel rail and new FPR

Post by Speed breeder »

Hi everyone

I installed a "7 bar" in tank fuel pump last year in my 200sx during building the car. Suffering from surging, I decided to install a autogauge fuel pressure regulator and replace all fuel hoses.

I left the original fuel pressure regulator on the fuel rail.

The car still seems to be surging.

The pressure before and after the new pressure regulator, which I installed directly after the fuel filter seems to be 3 bar only.

I have connected the fuel pressure regulator gauge before the FPR and an additional electronic pressure sender after the FPR which sends the signal to a gauge inside the car.

Both gauges indicate the same pressure.

My questions: Why would the pressure be so low if I purchased a 7 bar fuel pump?
What is the original fuel pump pressure delivery?

I will replace all the fuel filters this weekend- i have one before the fuel pump and one in the engine bay before the fuel pressure regulator.

The one in the tank is to protect the fuel pump.

The fuel pump is not a Mr Turbo pump but a bosch type which actually says 7 bar on the head, cost R700.
veecee
AGENT SX!
Posts: 7354
Joined: Wed Nov 08, 2006 3:49 pm

Re: Fuel pressure regulator on fuel rail and new FPR

Post by veecee »

Speed breeder wrote:Hi everyone

I installed a "7 bar" in tank fuel pump last year in my 200sx during building the car. Suffering from surging, I decided to install a autogauge fuel pressure regulator and replace all fuel hoses.

I left the original fuel pressure regulator on the fuel rail.

The car still seems to be surging.

The pressure before and after the new pressure regulator, which I installed directly after the fuel filter seems to be 3 bar only.

I have connected the fuel pressure regulator gauge before the FPR and an additional electronic pressure sender after the FPR which sends the signal to a gauge inside the car.

Both gauges indicate the same pressure.

My questions: Why would the pressure be so low if I purchased a 7 bar fuel pump?
What is the original fuel pump pressure delivery?

I will replace all the fuel filters this weekend- i have one before the fuel pump and one in the engine bay before the fuel pressure regulator.

The one in the tank is to protect the fuel pump.

The fuel pump is not a Mr Turbo pump but a bosch type which actually says 7 bar on the head, cost R700.
3 bar pressure after the regulator? interesting.

the stock regulator should limit the pressure to 2.5-3 bar. by adding an adjustable FPR and leaving the original (stock) one there, you kinda negate the use of the aftermarket one?

after the FPR though there, its just a run off back to the tank, and i'm not sure if my logic is correct, but there shouldnt be much pressure on that line at all.
ReeceZ wrote:I'm sorry... I couldn't help it. Please no one wish any hateful shit on me, I own an SX already
User avatar
Speed breeder
0.7 Bar Boost
Posts: 741
Joined: Wed Jun 06, 2007 10:19 pm
Car: S13
Location: Roodepoort

Post by Speed breeder »

The second gauge is in the fuel delivery line to the fuel rail.

How do I go about removing the original FPR, as it looks like it forms part of the fuel rail?

How many connections would there be on the the aftermarket FPR?

I have one fuel line going in and one going out of the FPR

The only other connection is to the "retard/advance/throttle body/pop up valve" line. There is no other hole or feed to run a return line to the tank.

I thought the return line would be fed from the fuel rail.
veecee
AGENT SX!
Posts: 7354
Joined: Wed Nov 08, 2006 3:49 pm

Post by veecee »

it does.

the stock FPR is the installed on the fuel rail near the firewall, or piston 4, or whatever else makes sense!

so on a stock system, the fuel rail is pressurised up until that point. once the fuel has passed the pressure regulator, it gets flowed back to the tank.

take pics dude - but post them here. dont keep them to yourself like chemcool would. he's been setting a bad example!

you can get a little adapter from most stores that will bolt onto your fuel rail in place of your stock regulator. its usually an alloy plate, with holes on the sides for the screws, an insert with an o-ring that goes inside rail, and a barbed or flared nipple on the other side that you can attach a fuel hose to!
ReeceZ wrote:I'm sorry... I couldn't help it. Please no one wish any hateful shit on me, I own an SX already
User avatar
Speed breeder
0.7 Bar Boost
Posts: 741
Joined: Wed Jun 06, 2007 10:19 pm
Car: S13
Location: Roodepoort

Post by Speed breeder »

Will Post pics...

In the meantime, does the stock FPR just pull out?
[/img]
veecee
AGENT SX!
Posts: 7354
Joined: Wed Nov 08, 2006 3:49 pm

Post by veecee »

you will need to remove the screws first, but then yes - it just pulls out!
ReeceZ wrote:I'm sorry... I couldn't help it. Please no one wish any hateful shit on me, I own an SX already
User avatar
Speed breeder
0.7 Bar Boost
Posts: 741
Joined: Wed Jun 06, 2007 10:19 pm
Car: S13
Location: Roodepoort

Post by Speed breeder »

Screws, hmmm...I recon me remove them wiff a hammer then huh...
Seems like a pretty dumb question I asked...sorry....
You can see I haven't paid much attention to the old FPR.
Cool Thanks for ur help dude.
veecee
AGENT SX!
Posts: 7354
Joined: Wed Nov 08, 2006 3:49 pm

Post by veecee »

NP.
ReeceZ wrote:I'm sorry... I couldn't help it. Please no one wish any hateful shit on me, I own an SX already
User avatar
ChemCool
SX Forumholic
Posts: 2195
Joined: Tue Aug 01, 2006 11:59 am
Car: S13
Location: Centurion
Contact:

Post by ChemCool »

you can get a little adapter from most stores that will bolt onto your fuel rail in place of your stock regulator. its usually an alloy plate, with holes on the sides for the screws, an insert with an o-ring that goes inside rail, and a barbed or flared nipple on the other side that you can attach a fuel hose to!
Tell me about this store please. where are these stores?? :roll:
COOLER, FASTER, LIGHTER
www.wappage.mobi AGENTS NEEDED URGENTLY!

Image
veecee
AGENT SX!
Posts: 7354
Joined: Wed Nov 08, 2006 3:49 pm

Post by veecee »

ChemCool wrote:
you can get a little adapter from most stores that will bolt onto your fuel rail in place of your stock regulator. its usually an alloy plate, with holes on the sides for the screws, an insert with an o-ring that goes inside rail, and a barbed or flared nipple on the other side that you can attach a fuel hose to!
Tell me about this store please. where are these stores?? :roll:
they should be available at most stores that sell adjustable or aftermarket FPR's.

when i bought my first FPR (which is for sale BTW) i got one of these little attachments for free, because i am a nice guy!!!

that was at volkspares in jet park. but i've seen them at many accessories stores!!!

or get gary to make some - its not difficult. i reckon you could make them with simple garage tools!
ReeceZ wrote:I'm sorry... I couldn't help it. Please no one wish any hateful shit on me, I own an SX already
User avatar
Speed breeder
0.7 Bar Boost
Posts: 741
Joined: Wed Jun 06, 2007 10:19 pm
Car: S13
Location: Roodepoort

Post by Speed breeder »

where do I get these simple garage tools...are we talking about the hammer again????


Just kidding...
veecee
AGENT SX!
Posts: 7354
Joined: Wed Nov 08, 2006 3:49 pm

Post by veecee »

hmmm lets see...

i would need a vice, a hacksaw, thread sealant, tap and die set, drill and drillbits, probably a pen and paper, and maybe some spraypaint???

and then the parts - a smallish piece of aluminium, the nipple thingy (check hydraulics stores), a little o ring.

thats it i think!
ReeceZ wrote:I'm sorry... I couldn't help it. Please no one wish any hateful shit on me, I own an SX already
Post Reply