58 replies to this topic

[rabidh]

What is pinking and how can you tell its happening?

It's engine knocking and you can hear it (hence the name).

Its not very much, but it just doesn't seem as smooth as before.

My bet is actually that its running lean. I think the FPR is just like normal FPRs and that vacuum causes the fuel pressure to decrease. With my OEM filter the vacuum in the inlet manifold rises at higher RPM and the fuelling decreases God knows what happens at low RPM though

andyroo - what have you done to your engine so far?

[andyroo]

andyroo - what have you done to your engine so far?

Personally; nothing

But it has an ITG in and a 2.5 inch Hayward and Scott exhaust with deleted precat and 100 cell cat out. It also has a Courtenay stage 2+ rr map.

[Crimson_Killa]

rabidh its also worth noteing that this solution was advised for people with induction kits as its that that causes the fuel pressure drop, i would guess that doing this to a car without induction uprgades wouldnt be a good idea as the air flow isnt restricted in the first place???? i might be wrong here but i wouldnt see the point in doing it if you dont have a viper / itg or equivalent??

[luna_s]

its a 2 (ok 5 second job ) to reverse it, see if theres any difference

[rabidh]

rabidh its also worth noteing that this solution was advised for people with induction kits as its that that causes the fuel pressure drop, i would guess that doing this to a car without induction uprgades wouldnt be a good idea as the air flow isnt restricted in the first place????

i might be wrong here but i wouldnt see the point in doing it if you dont have a viper / itg or equivalent??

I removed the small exponential horn in the air filter box (and moved the inlet pipe much further out) and immediately noticed a drop in torque - after reading this I assumed it could be due to a loss of vacuum in the inlet pipe so I thought i'd give it a go. Presumably i'm somewhere in between the two now though, so I don't get enough airflow for the mod but get too little vacuum for it to work well as original!

I must admit I like the idea of putting a small valve between the pipes so I can switch to the mod for economy when i go on a long motorway cruise!

Edited by rabidh, 08 August 2007 - 08:52 AM.

[Jase_MK]

Presumably this stuff would do?
http://cgi.ebay.co.u...VQQcmdZViewItem

or

http://cgi.ebay.co.u...oQQcmdZViewItem

(3.5mm v 3mm ID)

Edited by Jase_MK, 22 August 2007 - 01:10 PM.

[JG]

can someone explain how the fuel pressure regulator works could it explain why my injectors are to quote CS 'maxed out' at 6700 rpm?

[leevx2.2]

Just holds pressure in the fuel rail .think of it like if you pushed a water hose with your fingers one side would have allot more pressure .

[techieboy]

How does the vacuum connection from the FPR affect the what it's doing?

[vocky]

I seem to recall the ECU adjusted the fuel injector duty cycle (using the lambda sensor to monitor the fuelling) so it made little difference after 100 miles

[JG]

yes put its controlled by a vacuum isn't it? which is all a bit messed up on supercharged cars.

[JG]

oops i started posting that after Lee's reply, it took me a bit or time to press post.

[vocky]

The vacuum does alter the fuel pressure, but the ECU still remembers what the fuel tables should be even if the fpr adjusts the pressure, fussy thing the z22se ecu

[techieboy]

FWIW, I drove around for a few months with the vacuum line off or falling off and it made chuff all difference that I could see.

[JG]

where is the fuel pressure regulator? in the rail?

[techieboy]

Yep, gearbox end of the rail.

[slindborg]

Technically the fpr should hold the effective pressure at X bar, hence the vac connection or boost in the forced induction case. The problem is if you are cranking in say 3bar (absolute) of pressure and the fpr cannot deliver the 3+X pressure and you start to run out of fuel...

[ant1]

Anyone got any pics of before and after sadly the old pics have gone.

[ant1]

Help anyone got any info on what pipe needs swapping, or a piccy?