GTS25 running lean

[skyla]

Hiya,

While putting my car on the dyno the other day, I got them to test the air flow ratios, much to my suprise it's running a bit on the lean side of things (running 98 octane fuel with octane booster).

I know that running too lean can cause detonation, but thats about where my knowledge of the subject ends, so I was hoping someone could shead some light on the subject for me please.

My question is what can I do to get it fueling right. Any one have any ideas where I should start to fix this potential nightmare.

your advice would be appreciated, thanks

Rachael

[doxximus]

s-afc would be a good investment me thinks

[Pva_Glue]

SAFC

[rs73]

Before spending out $$$ on SAFC then finding out changing the setting on SAFC doesn't do anything to improve situation, maybe you should check first whether your fuel pump is heatlhy or about to die, or your injectors are dirty and not flowing enough fuel....

If they're both healthy, go buy SAFC and tune it to richen your A/F at desired rev points.

[rb25]

Rachael - what mods have you got?

I'd be checking anything that feed fuel to the engine, pump, filter, injectors, etc. And I'd be checking anything that measures air flow/volume/pressure as well like the AFM before blowing money on a SAFC. Maybe an ECU reset might help too.

cheers

[skyla]

Thanks for the speedy replies guys,

My mods are K&N panel filter, extractors, and 2 1/2" exhaust. The fuel filter was changed 12,000km ago, I generaly change it every 15,000 km. I run injector cleaner through the fuel every few tanks, and the ECU was reset 1000km ago. To be honest I'm a service nut.:crazy:

Righto, the AFM sounds like a good place to start, is it something that can be tested a home or will it need to be done by a mechanic?

thanks

Rach

[rb25]

can you borrow an AFM from someone?

[skyla]

After talking to a mechanic today, he suggested a fuel pressure regulator would be the best thing to do for a quick fix.

As checking the rest of the system is pretty much a process of deduction, replacing the parts untill the problrm causing culpret is found. (me thinks it's going to get very expensive)

[rb25]

good luck with it Rach, let us know how you go

[NA_R33]

u can buy my SAFC II if u want

[skyla]

I'll get one some day, at the moment my wish list is bigger than my income:(

[NA_R33]

i hate that

i have to sell all my goodies that will be no use to me with my new engine otherwise ill never even get started. chance are ill sell the goodstuff and never get round to doing the engine and be driving round in nothing more then i a riced up line hopefully that wont happen.

[Greg]

john mate how much are u asking for your safc II? i might be interested

[NA_R33]

bout 500 bucks, not totally sure yet though.

[Guest albert19]

What's AFM & SAFC? Sorry guys im new to this.

[NA_R33]

AFM = Air Flow Meter

S-AFC = an apexi computer "Super Air Flow Controller" it intercepts the signals from the airflow meter and tricks ur computer into thinking it has either more or less air, givving u the ability to adjust how much fuel the computer gives ur car in return.

[Guest albert19]

Thanks for that one!

[NA_R33]

no prbs

[Guest R33Glenn]

Hey guys has anyone had any expericence with the Mines VX ROM ECU?, i was looking at one on the perfect run site, it looks the goods, and a fair bit cheaper then the Apexi ECU.

[skyla]

Would a dirty afm cause the car to run lean?

I cleaned the afm today as it was black with dust, and had little bits of plant and insects stuck in the mesh, now the car idles alot better.