Ecu pic question

[samual]

Hey guys. Finally got home laptop talking to the ecu. It's an EMS Stinger. I got some questions. Today's is about Air/Fuel ratio.

Now am I right in guessing the lower the number the richer?

In this pic it's sitting at 15ish? That right at idle? It just smells rich when cold.

[Damo]

Unless it is a wideband sensor your ecu is reading from, i would disregard what it says. Besides, a 15:1 ratio would be very hard to get a stable idle out of, unless it is above 1500rpm or so. You either have a exhaust leak pre sensor, or the engine is missing like a bastard!

Damo

[samual]

Well I dont think i have an wideband sensor.

Its idles pretty good, except for every 5 or so secs it misses a beat, but generally it idles fine.

The car runs great. i just starting to learn about the settings that have been done by the tuner..

Does it need to read the A/F all the time to run? Or once the map is done on the dyno it does not need to read it?

How would it be reading my A/F ratio if I can not see an o2 sensor on the exhaust?

Whats a exhaust leak pre sensor?
and where would it be located?

Thanks Damo for you reply.

[tassuperkart]

Errrm.. if you dont have an O2 sensor fitted, then ignore the reading.
Even a WBo2 sensor will not read correctly unless you have the associated electronics to actually run it correctly THEN interface with the EMS.

L8r
Oracle

[baz]

14.7 is a spot on mixture, anything over that is considered lean & anything less is rich, Try for a 14.5

[shanec86]

yeah well 14.7 is just stoich, not really any good for actually driving the car.

In the E15ET you want to around Mid 12 to high 12's on boost (and WOT), and cruise would want to be around 13.6-14.0. Anything in the 14's would be fine for idle, and if its running fine on idle theres not much point in changing it.

and like has been said, that's only going to be accurately read with a wideband sensor + controller. a single wire narrow band is only good to tell the car when to move in and out of closed loop

remember the map you have open there is the BASE map. To properly tune it you need to be in the trims/fuel compensation section

[samual]

this has been properly tuned.

I not going to change anything just looking and learning.

Thanks Guys

[Damo]

I would verify that it doesn't have a O2 sensor first. If not , get hold of one so you can see what the engine is doing regarding fueling, not to change anything, just to see.
Does the afr reading change on the laptop screen?

Damo

[samual]

Yes Damo.

I will get an Sensor put in but it needs to be a Bosch one from what my ECU manual says. It even gives me the model number for the sensor, wish I could use a cheaper one as its about $250..

And I not been for a drive with it yet as I need someone with laptop in the front seat to read it and tell me whats it doing.

I can not see an O2 sensor anywhere on exhaust.

I let you all know later.

If anyone has a wideband Sensor for sale let me know.

Thanks Guys

[tassuperkart]

Any movement of the EGO display with no sensor connected indicates noise or RFI back into the ECU.
Are the ECU grounds connected to the original earth point on the engine or somewhere else.
If connected to the original earth point on the plenum then run a decent guage earth wire from there directly to the battery and ENSURE that your big earth straps are clean and tight.
besat practise is to earth your ECU directloy to the chassis, NOT the engine.

AEM sell reasonable WB2 controllers and sensor for around 200 bucks off Egay.
They also have logging capability and a serial output.
I reccommend these to anybody.

As far as any other EGO sensors, they are little more than something the ECU uses to invoke closed loop fuelling and are to be largely ignored as their display resolution is useless for tuning in any way.

L8r
Oracle