Two questions..... EGR and Fuel Corrections

[osullivant]

I have been having trouble for weeks, am still getting MAF 135F, despite fitting a new MAF and TMAP and Exhaust gas Sensor... Now that I have VIDA working maybe things will improve....

This clip was captured shortly after I got VIDA to operate following a drive, when I stopped the Air Mass/ Stroke was showing a value of nearly twice the Mass / desired until I hit 2000 rpm when they pretty much equalized, and this remained. My instinct now is that this is an EGR problem, I took this off yesterday and it is now the cleanest EGR in the world but It was extraordinarily difficult to move it as if the motor was seized...

When I got the camera out and recorded it there was only a little discrepancy

https://drive.google.com/file/d/0B6H...ew?usp=sharing

the above shows readings at idle through 4500rpm

Can anybody tell me if the EGR appears to be doing the right thing??

My Fuel correction/cylinder speeds at idle with a hot engine are as follows.
1. 689 r/min 2. 694 r/min 3. 689 r/min 4. 702 r/min 5. 692 r/min

1; 0.02 -0.02 2; -0.22 -0.4 3;0.14 0.11 4;-0.56 -0.68 5; 0.82 0.75

are these good bad or indifferent.... can injector issues reflect in a MAF fault??

Thanks

Tony

[cheshired5]

When you follow the path Diagnostics >Vehicle Communication >ECM, there are tabs marked Parameters and Activations.
In Parameters, you can choose up to 10 readings to be displayed and if you single click on any, a "Description" icon will be bold towards the bottom left.
You can then scroll through all of the descriptions which will tell you what is normal and you can then compare with your figures.
The same applies in the Advanced tab for fuel correction and it explains how to interpret the correction readings.
You should also be able to activate the EGR and compare the % open figures.
You can browse all these checks offline without Dice being connected to the car but obviously doing it live will shed more light on any problems.

Hope that helps.

[osullivant]

Had a look and it seems my Air mass/stroke (mg/s) and Air mass (kg/h) are both down to about 60% of what they ought to be. also theEgr seems stationary despite reving to 4500.

food for thought!!!

possibly new MAF needs to be adapted... but I suspect this is cutching at straws.

[5cilinder]

If you idle more than 2 minutes the egr valve is closed by the ecu hence the higher airmass then desired airmass

[osullivant]

Originally Posted by 5cilinder

If you idle more than 2 minutes the egr valve is closed by the ecu hence the higher airmass then desired airmass

Sorry ... I do not understand that point. In the clip I was reving to 4500 having been idling for quiet a while following a 20 minute journey.....at all times my Air mass is much less than the desired airmass......are you saying the EGR should not open unless I am actually rolling.....

I have some time to spare this morning so more analysis and head scrstching to be done..
Tony.

[cheshired5]

I had a MAF fault with low and erratic figures so needed to check if there really was reduced airflow or if the sensor was duff and unable to react to airflow changes.

I removed the MAF from the air box but left it plugged in to get readings and simply blew on it.
It produced the same duff readings but blowing on the working replacement gave the expected rise and fall in airflow readings.

Simple but effective MAF sensor troubleshooting.

[5cilinder]

Originally Posted by osullivant

Sorry ... I do not understand that point. In the clip I was reving to 4500 having been idling for quiet a while following a 20 minute journey.....at all times my Air mass is much less than the desired airmass......are you saying the EGR should not open unless I am actually rolling.....

I have some time to spare this morning so more analysis and head scrstching to be done..
Tony.

If its all the time youre egr is always shut (programmed/tuning ) , fault or your maf is faulty