250 Km From A Full Tank. Dam This Sux

[WogsRus]

Ok guys. so as most of you know i have had a meriod of little issues, in regards to cold starts and stubles at low rpm high boost and low TP%.

HOWEVER also added to that my fuel ecconomy is shocking. It's down to 250 km per tank. That sux, use to get atleat 350 or more.

The 02 is good, tried a new one made no differance. Tested for vac leaks can't find any, vac at 17mm HG at idle where is use to be always.

My new splitfires come in today as my old ones got fried, so that might help a little, and the car is getting retuned next week.

But surely you can't use that much fuel in a 2.5liter engine.

I run 15 psi boost, all town driving, exhaust is free, no leaks in exhaust and so forht.

Does anyone know if i take out the sensor form the cat, will that improve economy at all.

[R33GOD]

it could be your a/f ratios are too rich. get it looked at on a dyno

[WogsRus]

forgot to add, there is a lot of backfiring going on.

Yeah will be tunning it, just wandering if there is anything else to check over.

[negativecamber]

AFM dirty as a bastard? spray inside the AFM with contact cleaner, its about $20 a can and can be found in most auto shops.

[WogsRus]

did that, plus put a mates AFM on, will try again just incase.

[Birnie]

Hopefully the tune will sort it out...otherwise, stop driving sideways!!

That eats the fuel everytime

Side note... looking at your signature.

What's a Central 20 ECU, and depending on what it is, why do you need an SAFCII if you have an ECU??

[Pauly33GTS-t]

I have the same problem and have had it for a while, lucky my car isnt a daily and just a weekender.

Need an ECU and a good tuner. It's your AFR's.

[WogsRus]

Central 20 ecu is an ecu that can be remaped for an R33, which Dr Drift can now tune and provide chips for. The SAFC II is in there mainly as an additional ready out, as i had it on the car when first purchased with the stock computer.

The car was tuned with the Central 20 ecu and the SAFC II for fine tunning, untill Dr Drift comes down to tas, and i'll get a complete tune.

Interesting to see why my AFR would change if i haven't touched a single thing.

thanks guys

[Pauly33GTS-t]

its called flat battery and you lost your map and now its back to the stock map, most likely.

The stock ecu is going "oh shit? wtf? more air? DUMP FUEL! DUMP FUEL!"

Edited July 4, 2007 by Pauly33GTS-t

[RBwhatever]

Green contacts? make sure all your plugs aren't getting build up in them. Use the contact cleaner in them.

All I can think of is:

AFM

O2

Green contacts

Fouled plugs

Blocked cat (can that cause richness?)

ECU is running mega rich

Atmo BOV

Water Temp Sensor

You haven't got an FPR that's turned up to some insane psi?

But you've already ruled some of those out.

Does the car still pull hard?

When driving and you back off the throttle does your boost/vac gauge read -20mmHg?

And yes a RB25 can be that rich. My bro had a CA18DET silvia and it did just under 300km to a tank regardless of driving style.

[RBwhatever]

its called flat battery and you lost your map and now its back to the stock map, most likely.

The stock ecu is going "oh shit? wtf? more air? DUMP FUEL! DUMP FUEL!"

But if its a remapped/chipped ECU, shouldn't the map be hard wired in, or in other words burnt into the chip? Thus requiring another burnt chip in order to do another remap?

[RBwhatever]

Boost leak? The ECU is registering air going through the AFM but its not actually making it there?

[WogsRus]

well the car pulls like a scoldered cat, makes massive power, well feels like it anyhow.

Yeah a new chip is required everytime you need a new tune. Read only chips.

in regards to

AFM - cleaner replaced ect- no go

O2 - replaced, checked working all ok according to consults

Green contacts - humm what, bad contacts, i cleaned most i think

Fouled plugs - new plugs used tried a few different heat ranges ect, no diif

Blocked cat (can that cause richness?) - humm cat? now where did i put that.

ECU is running mega rich- possibly that is next weeks check

Atmo BOV - nope stock

Water Temp Sensor - checked values and cosult, appear ok.

You haven't got an FPR that's turned up to some insane psi? nope but if i do makes SFA differance, have had it at 70 psi.

When driving and you back off the throttle does your boost/vac gauge read -20mmHg? YEP SURE DOES.

[Guilt-Toy]

get a power fc for it and pay a workshop a MIN of $400 to tune it.

[WogsRus]

PFC are over rated and over priced, and retunable ecu like mine is far better, i get to keep my knock maps and so forht and a chip and a tune is $200.

JUST no one does it in tas. LOL.

[Guilt-Toy]

i wish everyone would get a power fc

good luck with it... sounds like your in for a bit of a mission getting the tune right down there.

[WogsRus]

Well PFC are esentially what i have but the chip is a hell of a lot more expensive, my chips cost $5 ea and tune time,

[R33GOD]

the dyno analysis is your best friend, do that

[RBwhatever]

Well PFC are esentially what i have but the chip is a hell of a lot more expensive, my chips cost $5 ea and tune time,

Was your car tuned by Dr Drift the last time he came to tas? Have your mods changed since then?

Edited July 5, 2007 by KeyMaker

[Guilt-Toy]

mm chips... I miss ruffles