Fuel pressure too high - what the???

PL · Post by PL » Tue Jan 01, 2008 4:27 pm

Hey Pingu,

Are there any hi-flow FPR's around that will go straight on without any messing about?

Thanks
PL

Pingu · Post by **Pingu** » Tue Jan 01, 2008 4:41 pm

On my ca18det i use a sard regulator - it's suitable for higher pressure fuel pumps. On the standard fuel pump it made a vibrating noise - i found out this was due to the flow back to the tank was achieved with a much smaller diapram opening. With a high flow pump it works great - the valve floats at a normal level and fuel pressure behaviour is great with a 160 LPH pump hard wired.

Will be adding an inline pump soon.

I highly doub't i'll see a similar issue.

There are two versions of the sard regulator - i use the lower capability model.

Pingu · Post by **Pingu** » Tue Jan 01, 2008 4:55 pm

PL wrote:Hey Pingu,

Are there any hi-flow FPR's around that will go straight on without any messing about?

Thanks
PL

As far as messing around - the adaptor to the rail is needed. I had one made, but i now know they are available for virtually every nissan.

PL · Post by PL » Tue Jan 01, 2008 5:03 pm

Sounds fair. I take it these are not a "rising rate" reg. Just a normal reg like factory but they flow a bit more?

Thanks for your help. It's not my car - but I tuned it, so I'll investigate this for the guy.

PL

Pingu · Post by **Pingu** » Tue Jan 01, 2008 6:42 pm

Hey - 1:1 as per factory. It's flow range is greater.
Base pressure setting range is 200-800 kpa - i set mine to factory spec (~38 psi with no bias from the manifold for ca18det)

Rising rate are evil. - added tuning complexity for no reason with most EFI cars.

Sounds like a regulation problem to me!

PL · Post by PL » Tue Jan 01, 2008 6:51 pm

Yeah, I'm with ya there. Suddenly all my "base maps" are useless if somebody fits a rising rate FPR. Big injectors are cheaper these days so there's usually little reason to use them.

PL

Fusion Ed · Post by **Fusion Ed** » Wed Jan 02, 2008 9:54 am

I hate rising rate ones too. I wont work with cars fitted with them now. They cause too many problems and you never seem to get good results with them.

PL · Post by PL » Wed Jan 02, 2008 10:48 am

I see NISMO make a FPR but they don't say what the flow capability is. They don't even say why it's better than standard. But you'd hope it was! The good part is that it looks like it would bolt straight on.

There's a bunch of eBay FPR's available too but most are generic types (of questionable quality) that will need to be adapted to fit.

Any feedback on experiences with specific units appreciated.

PL

ByReaL · Post by **ByReaL** » Wed Jan 02, 2008 10:54 am

Bought a SARD one the cheapest version , with a fuel pressure gauge, in my opinion it works ok (replaced the old one because it was old, because i wanted to be able to adjust the fuel pressure and because it has a gauge)

i manufactured the adapter for the fuel rail, for the CA18DET but i understood the Subaru fuel rail adapter will fit the CA18DET

so what can i say i'm happy with it spent 200USD, but no difference in performance compared with the standard one. (i use it on standard fuel pressure and anyway i ave 720cc injectors)

Fusion Ed · Post by **Fusion Ed** » Wed Jan 02, 2008 7:38 pm

I have used many sards and had no problem, infact i like genuine sard regs. Likewise I have used aeromotive FPRs and they seem a fine (but a bit too bling, the return does seem look a bit small but had no problems on 600+bhp engines with huge fuel pumps.
Nismo too I have had no problems. The strange shape 'FSE' ones however (rising rate) have caused me no end of headaches.

RB30-POWER · Post by **RB30-POWER** » Sun Jan 06, 2008 5:04 pm

i haven't read all this thread, but if your having trouble with fuel pressure being excessively higher then standard, or the pressure will not drop when adjusting the regulator lower (if its adjustable type).

remove or disconnect the return line from the regulator and put it into a bucket/suitable container.

if the pressure immediately drops to standard pressure, it indicates a blockage or flow restriction in the return line somewhere. (compressed air will blow crap out, if its crushed somewhere, it may need replacing)

if the pressure does not drop at all, when the return line is disconnected, and you need a lower base pressure, get an adjustable regulator and lower the pressure, by adjusting the pressure on the diapraghm on the reg. (they all adjust this way)

otherwise there is no need for adjustable fuel pressure regs in most applications, if your not trying to either lower or raise the pressure.

nismo regs are good (especially if you want OE look, they bolt direct to the rail, and used by Gibson Motorsport on the Group A GTRs back in the day) sard are very good value for money (what i use) sx are good regs, very exxy but, (get what you pay for) malpassi are crap, eradic pressure changes with temperature, failures are common, wouldn't recommend these to anyone myself.

PL · Post by PL » Sun Jan 06, 2008 5:33 pm

Yeah, tried the "return into a bucket" trick first up. No diference. Looks like we just need a reg that's capable of flowing more fuel (currently running std). Might grab a Nismo.

PL

nisn · Post by **nisn** » Sat Jan 26, 2008 1:15 am

hey pete howd ya go.. im usen 1 of these,for two years no dramas yet. http://cgi.ebay.com.au/Adjustable-Fuel- ... dZViewItem ps old thred,but my 2cents.

PL · Post by PL » Sat Jan 26, 2008 9:19 am

I haven't re-visited this one yet. I tuned it before Xmas but then the owner was running off to get married and stuff so I'm expecting a phone call some time about it.

I suspect he'll just go the NISMO reg seeing as the car has been "enginneered" with SR turbo etc. In SA we're (theoretically) supposed to leave the engine all standard once it's been approved so anything that keeps it looking standard is good!

PL