VE needed retune after firmware update?

[tom70]

I have just updated my firmware from 1.0.53 to 1.1.96. Prior to the update, I have also installed new set of injector FETs.

It seems that the engine running very lean now.

Initially, when it was in 1.0.53, the Fuel req was 6.5 and been mapped running very well.

However after the update, I couldn't get the car idle properly unless I increase the Fuel req to 7.5 and crack ignition advance to 5 deg.

Wonder if someone can go through my log file and have a look please? And let me know if the car needed a remap again.. which is going to cost me a lot of money...

Fuel req 6.5ms... poor idle v3.3_n000608-2011.10.23-17.22.36(6.5ms).vemslog

Fuel req 7.5ms...running lean but idle OK v3.3_n000608-2011.10.23-17.24.39(7.5ms).vemslog

Fuel req 10ms... same as above v3.3_n000608-2011.10.23-17.52.54(10ms).vemslog

Please note: the coolant temp is showing alot hotter than my actual water temp gauge...

Many thanks in advance

[tom70]

I have also found the old log file when everything was running sweet (before FETs and firmware update)

Need old VemsLogger to view it.

log1.xls

[rob@vems.co.uk]

Theres a load of auto tune functionality in the new software to help with this, the key part you needed the dyno time for was the ignition - thats fine as its untouched, the fuel can be addressed with the use of the wideband to lean out the map, then use the tune by statistics function to smarten the fuelling up.
The new acceleration enrichment will really help with the throttle response.

Rob

[tom70]

Ah I see, is it common that we need to retune the VE after firmware update? Or there might be something wrong going on?

[rob@vems.co.uk]

I think its the case - the fuelling has been reworked in the new firmware.

[gunni]

Probably the case of more scalars coming into play.

[tom70]

Cool, I will have a play with it this weekend.

It looks like VEMs has become better and more user friendly.

I have yet to test the new injector FETs at the limit.... will see how robust the new FETs are.

[tom70]

One questions on autotune,

What EGO close loop control limit would you use? -3% and +1% ?

or -40% and +40%?

[gunni]

thats not a autotune question.

but I stick to 5% most of the time.

[tom70]

My car is still running super lean (from Vemtune readings). Feels OK and strong to drive.

However, if use auto tune and VE analyzer, the car won't even drive properly and feels super rich (like in limping mode, VE 120 at near idle!!) although the vemstune is showing good lambda reading.

I guess is that my lambda sensor is shot.

[rob@vems.co.uk]

It doesnt necessarily mean that the lambda is shot - check the map that the thing generates, does it look sensible?
Using datalogs and some help on here you can very simply get the fuelling right - looking at the datalog will show you where and when the map needs fuel added or removed

[tom70]

The reason I think the lambda is shot is because I had the injector running wide open at too many occassion when my FETs died. Also, the lambda doesn't read unless I give my car a good blast at high engine speed and WOT. Otherwise, it will never read.

This is the map I manually created which will run but slightly lean (as lambda suggested):


This is the log:


This is the result after VE analyzer:

[tom70]

The will struggle to pick up any speed if I follow the map as per suggested by Autotune or VE Analyzer. It is running way too rich.

[rob@vems.co.uk]

Well the analyser programs need really good lambda readings in order to work correctly, so they will produce bad results.
Excess fuel can result in a dead sensor.

[tom70]

That's what I think.... I guess, new sensor from the shop then...