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well ive gone through just over half a tank after changing the O2 sensor and fuel economy seems to be unchanged, i will be changing the air filter to a K&N equivalent panel filter, perhaps that may make a difference.

im running out of ideas, ive already changed O2 Sensor, fuel filter, used injector cleaner.

anybody have some other ideas?

Had the same problem but have not actually got around to changing my 02 sensor, its still just unplugged at the moment. Mileage went up by about 80kms per $60 of petrol though. Not sure whether it will get better or worse when I plug it back in with the new one. Before I unplugged it it was running so rich I'm sure there was raw fuel coming out the back end :dry:

Lead foot does play a big part though. Drove from Hamilton to Auckland (about 80km) like a Nana then drove a 3rd of the way back (about 25km) at 120km/h & I had used about twice as much gas as I did for the whole distance of the original trip. Went back to driving like a Nana for the remaining 55kms.

Edited by tRUkbOY

my latest tank yielded 263.6km for 61.06L thats 23.16L/100Km

...thats rediculous!

i admit that i gave it a bit of stick on this tank of fuel, however its starting to be beyond a joke, when you consider the car is mostly standard.

it seems to be getting progressively worse as each tank passes, so im leaning towards the problem being with the airflow meter.

i'll try and get it checked/replaced soon to see if its the problem. anyone got an idea of what they are worth?

agreed - get a Z32 afm. There was a group buy recently for around $300.

or 2ndhand ones are around the $200 mark, same for a Q45 afm.

both q45 and z32 'read' more than a standard rb25afm..............

then tune the a/f ratios with a SAFC and you'll get better mileage!

my mileage has gone down hill big time, using 15kms more per 1/4 tank, since I intsalled the free flowing CAI box. I need a retune of the SAFC but its too damn expensive........ need to save up for the bigarsed turbo first!

well i bought the standard AFM from wolverine (cheers heaps for that Andrew) and ive fitted it to my stag.

i noticed straight away that the small amount of backfiring i used to have, has ceased, so hopefully it will answer my fuel economy crisis.

I went and filled up my tank at the servo and reset the trip odometer, so i'll let you guys know the outcome.

I switched from my 19's to 16's a couple of weeks ago, as decided to get new rims.

Anyway in the last 3 week's l've been getting about 75km's more a tank than l was when l had the 19's, which surprised me that it made that much of a difference.

Getting 18's next week ... hopefully it won't change too much with them.

WOOHOO!!!

after replacing my AFM with the second hand one that i bought from wolverine, my fuel consumption has gone from 23L/100Kms to 14.3L/100Kms

the backfiring did come back, so a tune with the DFA will increase it even more. ill probably get it done once ive finished my exhaust

>_<:D:D:(:):D:D:D:D

To increase my fuel ecconomy I went out & bought a little N13 pulsar!!! Now instead of spending $80 per week on fuel just to go to & from work, it now costs me $70 per f/n to fuel both cars!!! I figure it'll take about 3 months for the pulsar to pay for itself in fuel & then i'll be saving $$$. (not bad for a $500 car!!!!!)

Plus i get the bonus of not clocking the km's up on the stagea!

If you knew a Stagea was only going to give you 15l/100k would you buy one. If the answer is NO, then you dont deserve a Stagea!

You gotta love Nissans to buy one. Fuel consumption is the last priority on the list.

But after you doget one, S1 or S2, there are many ways to improve fuel consumption.

At the moment I am building a Jaycar DFA,a Smart Fuel mixture Display and a Hand Controller.

Thats the first step, and I'll keep an eye on the O2 sensor and the A/F sensor.

I'll keep you posted.

thats it mate, i just enjoy the drive these days and just accept the cost. Its completely worth it. FFS 15L isnt THAT bad really.

My mates dad's 550 maranello has a 110L tank and drinks 2 of those a week when it was a street car (work and back + some fun)

I've had the DFA in the car for a year now, and it still pops when you pull back into second gear on the overrun (that is probably the 3 inch exhaust working there).

In any case, just reporting in that I got to drive the thing (an old series 1 stag with auto) for a full tank on the highway, down to the goldcoast and back, then up to the sunshine coast and back to Brisbane, then back up to Bribie last week. With the mods as mentioned in post 58 of this thread, it went 583 km before the light went on. When I filled it back up, it took 58 Litres of BP ultimate. Result ! thats 9.95 L per 100 km. whohoooo, into the 9's !

The thing is tuned lean at cruise (15.5: 1 air fuel ratio) using the DFA and a wide band O2 sensor, no need to take it to a dyno shop for the tune, with the wide band in the car, you tune it as you drive. I know its supposed to cruise at 14.7: 1 in closed loop, but there must be a limit to the amount of trim the computer pulls back into the cruise mixture over time, so if you monitor the fuel ratios every month or so with the wide band, you can see at the start the computer tries to put fuel back in, but after pulling fuel out again the second or third time, the computer must run out of trim in the cruise load zones, thus I can happily cruise at 15.5 to even 16:1 and get an additional 8-10% fuel economy. It is a little doughy at cruise, but the additional ignition advance which comes in at the same time when tuning with the DFA helps there.

The clincher has been the revised valve body in the auto, which helps it hold onto the lockup on the converter longer, and also the fact that it seems to get 5- 8% better fuel economy when running on BP ultimate compared when it runs on optimax. Dunno why, obviously ultimate is a different fuel composition, but it certainly gets better mileage on BP ultimate.

Anyways boys, try to beat that on the highway and get yours into the 9's.....

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