Running rich or lean

[Tricky-Ricky]

They look pretty normal to me, a bit rich at idle and low load, which is the black around the peripheral, but the electrodes are a pretty reasonable colour,which indicates to me that the problem is low down in the RPM/load range.(two look slightly lean, but I would lay money that they are the back two, so normal)

[mellonman]

Ric your sure the resetting of the stock ecu wont have a effect? If the feul trims are lernt on the stock ecu lets say as he has 550 injectors the stock ecu sets a -5 trim and then obtains stoich.then the car is mapped with the emanage all trims long and short are are mapped from there lernt point , so when resetting the stock ecu the trims will go back to 0 giving the emanage closed loop map a +5 on what ever its map was.

A good way to tell this would to watch his afr when cruising off boost and idle to see if the afr fluctuate say 13.3 to 13.9 if they are constantly bouncing between figures like above then I would say its a fuel trim learn and if driven for a hour of so should return to 14.7,

 

I dont know the emanage and what it uses as signal for closed loop and how much it uses the stock ecu,

Also if the gap on the plugs are too large you might not be burning all the fuel which might affect afr but I doubt this as I would have thought a misfire would appear

[Tricky-Ricky]

The EMU is basically set up as independent from the std ECU, other than the global injector compensation, in general I have never needed to tweak the EMU for idle (unless you count the lag settings which can be a bit of a pain) and the same goes for low load/RPM, in fact with the Supra on a single turbo you shouldn't need to touch the maps (other than timing) until you start to make boost, as the std ECU does a very good job of things.

 

I think your saying that if the std ECU was not reset when the EMU was installed and then rest would it make the std ECU not correctly relearn the idle/lambda feedback? the answerer would be no, as its would just be normal feedback as the injectors are already compensated for with the EMU so the std ECU thinks its got std injectors, that why you really shouldn't even try to use the EMU for closed loop adjustment, as the std ECU will just fight it all the way to keep its version of stoic,

The only scenario that I can think of is if the injector change setup is incorrect, and the std ECU is trying to bring things back to stoic, and hasn't got enough adjustment, so despite trimming the injectors to reduce fuel it cant get things back.

Hope I have explained what I mean and not further confused things. LOL!

[ballsdeep]

Its unlikely to be the FPR as the rich mixture would likely carry on through the load range.

 

Booked in for the 26th but I still can't help thinking about it, I tried another short boost run and I'm now thinking its also running rich on boost too? I'm Sure I saw the afr's go into the low 10's also when looking at my boost controller it seems to be rather quick to go into positive boost..?

 

what else would cause rich conditions through the entire load range?

 

Sorry if this is obvious to some, I'm still learning

[Wez]

what else would cause rich conditions through the entire load range?

 

Larger injectors that are not being compensated for.

[mellonman]

yeah could be something as simple as injector response time being out , your afr don't seen to far out to worry about or loose sleep over though

[ballsdeep]

I'm feeling rather frustrated today, anyone want to buy my na-t so after having my car looked at I was told the map needed some adjustments so even though a stock ecu reset should not effect the map I paid the man and was just happy it was sorted. Little did I know it wasn't the end my troubles!

 

for the first 20/25mins It was perfect, idle and cruise was at 14.7 with WOT at 11.5 then very slowly it started leaning out, by the time I got home it was mid 16's idle / cruising also the idle was lumpy and the car was Bucking / stuttering while crawling at low steady Speeds.

 

So Iv gone from running rich to now running lean

[Tricky-Ricky]

Sounds to me like its the way the EMU injector adjustment/compensation for the larger injectors has been done, and or faulty EMU but I doubt it, who is mapping it? and just how much experience do they have?

[ballsdeep]

I hope it's not faulty i bought it brand new a few months back, it's being done by tuning development, its going back Thursday for them to check it over but he's questioning how it can go from being perfect for them on the dyno and the road test to suddenly start leaning out!

[Chris Wilson]

Do these things have data logging? If so then you need to read the data!

[ballsdeep]

Still not quite out the woods yet,

 

to recap - I reset the oem ecu which made the car run slightly rich but drove perfectly just how it use to before the reset so I took it back to have the map looked at to which I was told it needed some adjustments. after arriving home it would slowly go lean and if the rpm was held between 1k-2k it would go lean and hunt.

 

So again it went back and now they have disconnected my lambda sensor and made adjustments and told me something is interfering and changing things that they cannot control via a piggy back ECU. (opinions on this please as I'm not convinced it's the way to do things?) it does drive ok but the hunting/missing and going lean while holding the rpm between 1k-2k is still there! Iv pretty much lost all confidence in there ability!

[Chris Wilson]

"Hunting" is usually a sign of excess richness, not a weak mixture. I have never got involved with messing with a piggy back ecu, so just what is happening I have no idea, but it's either faulty, mis-wired, the O2 sensor (presumably a proper wide band one?) is faulty, or the map is wrong.

[ballsdeep]

My money's on the map, they did do a good job once before but the last few times Iv not been impressed! if it wasn't for the strange behaviour while raising the rpm at idle I'd be happy. il try and get a Video up tomorrow!

 

Could a dirty injector maybe cause very light hesitation under low load, erratic idle and the hunt while holding the rpm? These are the symptoms I'm getting when fully upto temp.

[Tricky-Ricky]

As Chris says, could be that your wide band needs calibrating or is faulty, however, they have disconnected the std ECUs lambda because the std ECU is trying to negate the fuelling adjustments that have been input to the EMU, because its an N/A the std ECU is set to be in closed loop with lambda feedback for a lot longer/higher load/RPM that the equivalent turbo ECU would, which is I suspect the main problem, unfortunately I am not familiar with using the EMU on an N/A.

 

It would depend a lot on the turbo you have and when it starts making boost, as obviously as soon as its making positive boost the fuelling and timing will need adjusting, and its this that's causing the problems, but I suspect that whoever is tuning it is not very familiar with boosted N/As and has tried to adjust things too much too soon, but in theory disabling the lambda feedback will help, but first they will need to let the std ECU adjust the fuelling so it will run slightly rich, which is the ECUs default for not detecting a lambda sensor, and then start to make adjustments to compensate, which is probably why its not gone weak.