Stale Fuel...

[Tony de Wonderful]

That is a Lambda of 0.9 at fast idle (3000 rpm)?

The only thing I can think off is that 'cos the easily burned volatiles have been lost from the fuel you get incomplete combustion or something and excess fuel in the exhaust???

The old fuel burning like crap to be blunt?

I did bypass the throttle-body coolant so I'm a bit worried that might be causing it as well though?

[Nanogrip]

Naw, bypassing the throttle body coolant won't cause such thing. Although, if it is in the winter, I fear that it might get stuck frozen open from cold air. No problems for me in this tropical island. Perhaps you had a bad batch of fuel? 16 oz. of toluene will fix it (or much more) unless it is illegal to add such additive to the fuel.

[.:: GimpS-R34 ::.]

you can get an octane booster if you think your fuel is off.. just baby it around till the fuel is gone and top up then check..

[Tony de Wonderful]

I forgot to mention I did add some octane booster about 3 weeks ago.

[Tony de Wonderful]

I was just wondering if my FPR could be set up wrong because it was only recently put on?

It's a Tomei one and I have a gauge on the FPR - the gauge should show the adjusted pressure yeah? So will be lower at idle and higher at boost?

What's it supposed to be on a GTST anyway? Is it 2.5 bar?

[Nanogrip]

Some octane booster isn't going to do much, and 3 weeks ago means today the fuel is back to stale. If nothing has changed except time, then the fuel could be still the culprit. Add 1/4th gallon of toluene, trust me, it isn't going to damage anything, in fact, I would recommend the whole gallon, but start off with 1/4th. Hmmm, other things to check are your fuel filter and fuel pump condition. Good luck and lets see how this unravels.