Gridlock Mikey

So we know that after certain mods, your car can run lean or rich. My question is this, without remapping the ECU, is there anything else that can be done to change the mixture. In days gone by, you could faff around with the carb and set the mixture.

Reason I ask is that recently I was told that the car was running a little rich but because it's a UK car, that's fine.

I'm ok with it running rich as it means bigger pops, bangs flames etc and also a little rich is better than a little lean, but had the diagnostic shown mega rich or dangerously lean, what, if anything, could i have done about it?

Just wondered

Mikey

Katana

You can change he fueling using an Air/fuel regulator. The cheap ones from HKS is about 100 quid whereas the Apexi ones cost in the region of 270 and above....unless you get it second hand of course.

scoobyslut

Not much you can do if still equipped with the standard ECU, but if running seriously lean, may cause the pistons to overheat and burn, normally caused by faulty MAF sensor, which is just a direct replacement unit.
Thats one of the reasons for Uk spec to run rich, as Jap models run leaner as they are normally run on higher octane juics in their homeland, which we cant get over here anymore.
So, thus brings about why jap imports have serious piston probs when in europe.

RRH

I have an HKS unit sat in front of me, brand new, that I bought for a project and never used. Paid £111 from JW Racing, open to offers.

simon

Katana

scoobyslut, jap cars only have problems if you run it on low grade fuel (95 RON) and whack it up on the boost. Thats why I use Optimax and a tad bit of octane booster.

RRH, but that AFR is only for slight mods only right? Still a good buy though if I may add.

[Edited by Katana - 11/22/2002 1:04:59 PM]

Gridlock Mikey

How do they work? What are they plummed into? The ECU?

Mikey

Katana

It changes the signal into the ECU. Dunno exactly how to fit it in yet, but once LegacyT has sent me the Apexi, I'll tell you the next day.

john banks

You can also fit a static or rising rate fuel pressure regulator, fuel pump, injectors. Extra injectors, injector controllers, induction kits - these will all have effects on AFR. Or replace a faulty MAF sensor.

STi wanna Subaru

iTrader: (1)

John,

Is the only way to check for a failing MAF to get the car plugged into either DD or the select monitor?

john banks

Or fit an AFR meter.. you can build one for £10 if you are decent with a solering iron.

STi wanna Subaru

iTrader: (1)

Am I correct in thinking a AFR meter takes its signal from the Lambda sensor? If so then could it be possible that if the AFR meter is showing lean running it could be due to a failing lambda but is more likey to be caused by a failing MAF?

Thanks

Guy

john banks

Could be either failing MAF of failing lambda. Next step is to measure the MAF voltage to decide.

STi wanna Subaru

iTrader: (1)

Thanks John

Gridlock Mikey

So you fit an AFR which tells you rich/lean, but how do you adjust it without remapping?

Mikey

Katana

With an air fuel regulator. Sorry if I'm confusing you with the air fuel ratio meter as they both seems to have the same acronyms.

john banks

Mikey, again:

"You can also fit a static or rising rate fuel pressure regulator, fuel pump, injectors. Extra injectors, injector controllers, induction kits - these will all have effects on AFR. Or replace a faulty MAF sensor."

Gridlock Mikey

So nothing then without it costing dosh or being some sort of mechanic or techie. No screw on the carb type fix here then Best go play with me Nova again

Mikey

Not that fussed, just wanted to know