Quick Question On Afr's

[Crans]

What should the afr's be hovering around at idle on an rb25det?

[zebra]

14.5-14-7:1 are around normal

[Duncan]

14:1 if the 02 sensors are working once the engine is warm

[Crans]

hmmm im getting much leaner than that have just cleaned my aac valve to fix idle and stall problem hopefully than helps o2 sensor was replaced just before i bought the car in october

[Crans]

ok shes running 17.5 - 18.5 on idle any ideas? o2 sensor was replaced less than 6 months ago.

[Adriano]

What are you using to measure that, and how does it run. That lean and it would be unhappy

[Duncan]

not just what, but where? Is there any chance of an air leak near the wideband sensor?

can you see the output of the normal sensor, how many volts is it showing?

[Crans]

Just put a hypergear atr28g4 ig on the stock manifold with vband dump with extra bung for a techegde wideband. I do suspect the dump is leaking alittle at the vband clamp. It sounds fine while idling. I can plug in a mates motec PLM in the tail end and check it.

[QWK32]

check how hot the wideband cabling is getting. i had an issue once with my techedge unit giving lean values, turned out the wiring was suffering from heat soak. but this was only happening after about 10-15min of driving once everything had warmed up.

[Crans]

Wideband cable shouldn't be the problem it dosn't appear to be getting hot. I will check out an exhaust leak being the problem. Does anybody use exhaust joiner paste when connecting turbo and dump via vband?

[Crans]

Ok I think i have fixed the dump pipe leak but still getting a lean afr but have moved into the mid-hight 16's.

Gonna start checking for vacume leaks.

[Dose Pipe Sutututu]

dumb question, but have you done a calibration on your O2? Not sure if tech edges need them, but Innovate & AEM do out of the box or else you'll get whacked readings.

[Adriano]

Thatll be it

[Crans]

Yeah i did do the calibration, I might do it again. I did do 1 stupid thing tho i had the wideband sensor pluged into the exhaust for alittle while while i was first sorting the bugs in my new system, but it was not wired up. Would this kill the sensor?

So basically the calibration was done on a dirty sensor

[Crans]

Just grabbed a compressed air can from work. We use them to clean out PC's from mine sites ill give the sensor a spray and re calibrate it

[Crans]

Calibration changed nothing. it wont be the sensor the cruize afr sit in the 14's perfectly fine any ideas?

I have checked for vacume leaks with a can of carbie cleaner and no change to idle.

Would a stuffed altinator cause the fuel pump\injectors to flow less? i did notice when i pluged in nistune that to voltage level is barely hitting 12v?

aslo sometime the wideband unit starts flickering to its heat cycle meaning not eough voltage to keep it hot

[D_Stirls]

If the O2 sensor is working and the ECU is going into closed loop then look at the fueling, a blocked fuel filter will lean out mixtures as the fuel pressure in the rail will be lower.

Just out of interest does the techedge O2 sensor have a narrowband output signal?

[Crans]

Yeah it has a nb output. didnt bother using it as my dump has 2 bungs

I'll change the fuel filter, where do you get them and what part code?