Wideband AFR readings?

I finally got my R back on the road today  

My car is fitted with Wideband AFR gauge. I'm just wondering what kind of readings should I expect when Im driving, It usually sits aroun 14.2 when ticking over and driving steadily wich I know is a good figure but what should I expect the numbers to drop to when I put my foot down etc?

Bob did explain to me how to use the gauge when I bought the car but ive forgot half of what he said lol.

Think under full pedal and boost afr's can drop to mid to low 11's. Thought on tickover afr's would be about mid 15's?

yep as above bill high 10s 11s on boost
14.2 is stoich and the perfect mixture at idle
partial throttle youll prob see 12s 13s
overrun sometimes afrs will really drop to 15-16s as you do not need fuel on lift off

Hiya bill how did it all go fitting it?
Hope it feels nice to have a running car again
Will drop the bits I forgot in the post this week for you bud

Cheers bob, the AFR reading seems to be about right from what you have said. It seems to be idleing high, like 1200-1500rpm, do you think perhaps I could have a leak in one of the boost pipes?

Paul the engine runs spot on mate, I've just took it for a good drive around and everything seems spot on. My mate that did the engine swap did it in one day, I wasn't expecting it back so soon so as you can imagine I was pleasantly supprised when he turned up at my house cheers buddy.

glad shes back up n running bill

whats the vacuum reading at idle on the boost gauge?

Just been out to check and it reads -0.5 at idle. When I started it just then the car was idleing at just over 1k rpm but when I was out earlier and the engine was warm it was idleing higher

have you tried turning idle down by the screw on r/h side of plenum near the tps sensor?

vacuum readings spot on

thing it's always idled around the 1000 mark since I had it dropped a bit once I changed the fan temp switch!

Glad all is running ok mate

will be a nice looking R on the road!

Thanks mate I've been enjoying myself in it earlier on today I'm still taking things steady at the moment though just to keep an eye on things, make sure all is well.

I'll check it out tomorrow and maybe try adjusting the idle screw if it's still idling a little high tomorrow.

I'm just realy happy to be out on the road again

Theres a pic on idle screw location  if you get stuck ...... in useful links section .... under diagrams .

nomad wrote:Theres a pic on idle screw location  if you get stuck ...... in useful links section .... under diagrams .

Cheers Leighton, I'll have a look, thanks

GTI-R US wrote:yep as above bill high 10s 11s on boost
14.2 is stoich and the perfect mixture at idle
partial throttle youll prob see 12s 13s
overrun sometimes afrs will really drop to 15-16s as you do not need fuel on lift off

Tbh Bob I think those figures are a bit rich on our cars. I think the skyline boys run those sort of figures and cossie boys used to back in the day.

Ideally on WOT you want to be seeing between 11.8 - 12.0:1 especially if you're running a permanent wideband and can see the fueling in front of you and keep an eye on it.

Some mappers will map richer down to 11.5 or even low 11's to allow a safe margin and obviously cover their own backs in case something goes faulty, but I get worried when I start seeing 10's as that's a bit rich and can possibly cause damage over long periods.

Stoich is 14.7:1 and you should be aiming for somewhere near this for idle but my car idles much better at around 14.0 - 14.2:1 and somewhere between 14 - 15 on part throttle driving. On over run we don't have any fuel going in so the gauge should go blank or off the scale.

These are what I've learnt over time and different people's experiences, and when I put my wideband on my standard car last year these figures seem to ring true. I've starting mapping my own car years ago using an AEM and the apexi afc and got to know about Nistune pretty soon after it was released and have used that ever since.

Hope that's helpful, Ben.

I took the car for a good run today, upon startup the idle was a little high and it soon settled to about 1100rpm but once the engine gets warm the idle creeps up to around 1400rpm and the AFR's start reading in the 13's on idles sometimes dropping as low as 13.2 on idle?

Under WOT I'm seeing as low as 11.2

Hardy172cup wrote:I took the car for a good run today, upon startup the idle was a little high and it soon settled to about 1100rpm but once the engine gets warm the idle creeps up to around 1400rpm and the AFR's start reading in the 13's on idles sometimes dropping as low as 13.2 on idle?

Under WOT I'm seeing as low as 11.2

Mines @ 10.7 on idle & 12 -13s off boost & 10.9 on boost, stillnot got round to looking at it yet tho, as ive got a bigger problem of a broken gearbox  

that's pretty much what I would call an ideal afr ben tbh but then im no mapper/tuner
from my experience and readings ive seen through the years stock ecu's tend to be overly rich on wot and run lean in other parts of the rev range dependant upon boost and many other factors

my gtir at the moment certainly hits the 10s on full boost but sits around stoich at idle so not too bad I guess.

gaz your readings are so wrong, really should not be seeing those sort of afr's at idle especially

bill........check for boost leaks and make sure there are no open vacuum pipes anywhere

What would be making it run rich on idle?, Not to fussed about WOT as its better to run rich than lean.

Just been for a drive around and the car started running abit shit, I looked at the AFR gauge and it had leaned off on idle and was reading like like in the 18s I just drove the car back steadily and the AFR's were fine when driving but would lean off realy bad on idle?

What do you think could be wrong? I'm thinking it could be a number of things

as said bill check for boost and vacuum leaks, make sure all pipes are tight and secure and theres no little vacuum pipes blown off especially round the inlet plenum near the injectors

Cheers bob.
I'm going to have a good check over everything tomorrow, I have been trying to secure that manual boost controller somewhere with cable ties so I could of pulled something loose when playing about with that.

I was having some fun with a EK9 type R then when I let the car idle I instantly realised something was a miss because the AFR gauge was reading like 18-20  And she didn't like it car was idling poor, very lumpy.

I'll go over everything when it's day light and see if I can find anything that could be causing it.

Well I let my curiosity get the best of me and whent out there with a torch and scanned all around the intake plenum and Yoda Bob with his infinite wisdom was right again  I had indeed blown off a pipe on the intake plenum right near the injectors

Happy days, cheers for that bit of advice Bob I've not run her yet because it's 1am and I don't think my mum will appreciate me revving it up while she's in bed  But I'll let you know how it runs tomorrow. I'm confident that's all it was a anyway. Thanks again buddy.

Just goes to show how handy the Wideband AFR gauges can be. I noticed something wasn't right straight away from looking at the AFR gauge, if it wasnt for the gauge i may not of noticed untill i had caused damage to the engine. It's a realy handy piece of kit and I'm glad my car has been fitted with one.

Just took the car for a short run and all seems fine again now.  

no worries bill glad you sorted it.

yeah one of the best bits of diagnostic kit you can buy for a car, if you know how to read it they can tell you so much
I wouldn't be without one now as saved my engine from catastrophe on many occasions

guys, i just install a wideband.. just wondering how was the afr of stock ecu on WOT?