AFR question
 

My mates hawk sti has been mapped on opensource,

It had a new lambda fitted 2months ago as he ws using a shed load of fuel.

issue went away but has come back now, so he got a mateto plug in a AFR machine and when its tickong over its 14.5-14.7 and normal driving around 13.

But when he opens throttle fully its hitting 9s,hes looked around for air leaks etc but cant see anything,

Hes going back to his mapper again inacpl weeks but wants to know what probs going into 9s would be and if anyones had anything like this before,

His tables are set for 10s and 11s whatever the hell that means:wonder:

On WOT the lambda will not be driving AFR, that will be down to the tables.

AFR of 9 is very rich, so borewash could well be a problem. I wouldn't be happy driving on WOT with that sort of AFR.

Could be all sorts of things not right ranging from a rubbish map, through to fuel pressure running too high for example. Air leaks are more likely to cause it to run lean, I would have thought?

I don't know about that model , but some standard bug fuel tables show as rich as 8.75
So I doubt it would cause bore wash if Subaru see fit to run that as standard
Has he seen his o/s mapped fuel table that are showing 10/11 or is that what the mapper has told him ?

He seen tables with them and was also told by his mapper ashe asked when he got it mapped so he said anyway.

This tables means nothing to me as its way above my thinking lol but

If the tables are the gosple so to speak then why would it go to 9 on the afr if its not in the tables, are the tables not the info the ecu needs or am i just spouting crap lol

Wow! My mini runs 11.2 - 11.6 at WOT on a standalone. 14.7 for cruising (lambda 1).
At 9.x my car wouldn't budge! LOL.

I once sprayed a load of meth in (by mistake) and it was so rich it sounded like a tractor :)

I am not a mapper, so sorry if I'm talking bill hooks...but I didn't think standard ecu (whether open source mapped or not) targeted a specific AFR in the tables, as they do not run a wideband.

My understanding is that the tables set out fuelling based in load, and that results in an AFR.

The mapper may have set fuelling up and measured a specific AFR to prove that the mapping was correct, and then something has changed meaning the fuelling is messed up. Or the mapper may have messed up the fuelling tables. Or I may be completely wrong lol.

If there no air leak, not on a rubbish after market dump valve then I would assume the map has a lean area within lambda control (cruise or idle) and the ecu is adding fuel to compensate and then updating the overall main fuel adder and hence richer everywhere as 13 on cruise is rich and why its using fuel. Will be down on power also

Simon

Thats just a number, it doesnt mean the actual afr is that.

Yes you are correct in thinking the table shows the ecu what to target , it will try to hit the target afr,s but like its been said , it could be bad mapping , or another issue ,
Is you're mate sure the afr gauge is 100% correct ?

It's all about what to input and what you get out , in order to for example archive a final result of 10.3 you may have to target a different figure in you're table , that said if all you're scaling and other tables are good I wouldn't expect to see a jump from 11 in the table and a result of 9 or vise versa ,
Well I don't get that anyway ;)

Sorry Tone but outside of closed loop the ecu cannot target anything as it doesnt have a proper reading of the actual afr.
It uses the fuel tables and maf curve and injector settings and other compensations (air temp, coolant temp) to come to a pulse duration to open the injectors for but dont actually target that afr in the table. Thats where one would hope it would be with everything as standard but in reality in never usually makes it without adjustment elsewhere to make it correct and the ecu doesnt know the engine is running that afr or not

Does he have an after market intake fitted? My guess is either a leak post MAF or the ltft D is adding lots of fuel.

(Repeat , that said scaling and other tables are good )

When I had a post maf leak it showed more on ( a )

Do you think it could depend on where the leak exactly is or how big that makes it show in different areas ?

I was meaning either or. I.e he has an after market intake on and it's not scaled correctly causing the D range to add fuel through to OL. Or, he has a leak.

Ok , thought you meant maybe a leak was causing fuel + in the d

I would have thought a mapper would at least check the closed loop was right
Seeing as that's the easy part !

Btw I must point out at this stage , when I posted my mapping method and one thing I did was the use of l/v on c/l to check my fueling was correct in that region and using it as a progression into o/l ,,,and was dismissed as a pointless exercise ( because it tells you nothing ) about o/l


Now low and behold folk are saying you need good c/l to help the ecu achieve
it's target afr in o/

Who's bulling who on here ?
Not a dig at you mate ,just thought I'd say ;)

:wonder::confused:

Lol, I'm not getting into this on someone else's thread. Start a thread Tony, this forum could do with more threads about the ecu operation/mapping.;)

Lol , I'll try and explain ( I'm not the best )
Your main fuel table is what you are targeting afr wise
You can't just tap in 10.3 in that table and the ecu will hit it
All things being good it can get close

Example if you have 550 injectors scaled at 650 it's not gonna fuel correctly , so regardless what figures you want to achieve in your main table the ecu won't be able to because it's onto a loser to start with
The same goes for maf , latencies, closed loop ,Ect ect

So if all you're scalings are good and all you're other tables ,it should be able to target somewhere near you're target afrs in your table

Give over mate , you know how how my mapping threads go lol

I'll second that m8.
After mine set and done, i'll start a thread stating all the work done, map data/values, power/torque etc so as to set a REFERENCE (should've done THAT before mine went bang; big-end bearing gone). . .
As it is now, the rex running at most 50% of its potential, with only max (as much as I dare) 0.8 boost with 58 knocks (not good), AND a full tank lasting only 4/5 days with conservative driving and minimal boost (terrible!)

If you have replaced the engine it needs mapping for the new engine.

Big ends usually fail due to oil related issues but if its not mapped or mapped very wrong then it could knock a bearing out but not normal.

[quote=Jolly Green Monster;10836283]If you have replaced the engine it needs mapping for the new engine.

Big ends usually fail due to oil related issues but if its not mapped or mapped very wrong then it could knock a bearing out but not normal.[/quote


its not a total engine change, only swapped the short block with a vr7, everything else was re-used (okay, changed the head gaskets, oil seals, all 6 of them, plus the 2 circular and 2 semi-circular cam seals).

the bearing on rod #1 totally disintegrated, eating part of the crankshaft, rendering it totally un-useable. Was thinking to upgrade to a 2.2 stroker kit but..ehem....the wallet disagreed :( ....that was right AFTER an oil change when i 1st used a moly 3000 10-30 ....less than 1,000km afterwards...BANG :(

[QUOTE=JasonVr5/7;10836456]was this with +8 degrees on the temp learn as you mention elsewhere?

Nope. Bfore the Big Bang, evrythng was 'hungky dory' . . .

So failure was probsbly oil supply related then.

I'd recommend reconsidering the +8 degrees your currently testing out though

Forgot to mention, the AFC was 'tweaked' a bit during the oil change by the so-called xperiencd tuner at the particular garage, which after the bang, prompted me to start revising the AFC etc (rekindled old habit).

Currently, aftr revising the injector values/latency; 61% +0.12ms, my temporary IGN/INJ are +3 0.800 due to still bits of black fumes frm the xhaust. Maybe it IS the o-rings that gave up . . .

Ok back on topic,

Latest update.

Ma mates now got the car running fine on boost but on start up its a bag of crap for the first 10secs or takes 3/4 turns before struggling to fire into life.instead of first time everytime,

Also on part throttle,so gradually building the speed up to 5k in any gear, it struggles and starts to dumpout the dumpvalve and losing boost but if ufloor it boost comes back,

Hes changed the genuine hks ssqv he bought 3yrs ago and fitted a baileys,then tried a turbos art and it does it with them all.

What scaling should 650cc injectors be at and why would the car lose boost on normal driving at 5k rpm but not when on boost and booting it higher,
Sould it not lose boost on full throttle rather than part throttle?

scaling should be for the 650 but latency will need looking at possibly.

Sounds like mapping issues.