E220 CDI running rich on fuel

[Asif Kazani]

Hi! Guys,
I would really appreciate if you could share your ideas and experience on this problem. I had a faulty glow plug replaced today and I thought it would be good to have the car checked throughly while it was on Star for the codes to be cleared. As I have been suspecting for quite a while, the car seemingly was running rich. We went to the CDI2 section on the star and "check values for exhaust gas recirculation" The Specified value of MAF showed 247-285 while the actual value hovered between 467-485. Does this seem incorrect? Due to shortage of time, my friend suggested that I bring the car in Tuesday since he has a friend, who is going to be visiting Karachi on Monday, who is an expert on Star.
The Star, however, showed no stored faults. As part of my trial and error plan to sort out smoking!?! I had replaced the MAF about two weeks ago with no difference in the performance or smoking. Are there any other sensors that can vary the fuel mixture on this vehicle???

Please Help!

Asif.

 

[Dieselman]

This indicates that the actual value of ingested air is way above the theoretical figure.
Either the EGR valve is closed so more air is passing the MAF or the MAF is faulty showing more air passing it.
If the ECU sees more air it will add fuel accordingly.

 

[Asif Kazani]

This indicates that the actual value of ingested air is way above the theoretical figure.
Either the EGR valve is closed so more air is passing the MAF or the MAF is faulty showing more air passing it.
If the ECU sees more air it will add fuel accordingly.

Thanks for your post Dieselman! Let's suppose for a second that the EGR is closed and more air is passsing through the MAF, would this not have perfect combustion since the ECU would be adding fuel accordingly?? Do you suggest any method for checking the MAF manually to see if it is working properly?

Thanks,

Asif.