Measuring Blocks group 75 EGR

D

dzikuss

New Member
Hi! Could anyone tell me where from does the inputs come from in the pressure field no 3? It's a differential value from map sensor and.....? I know that test difference should be at least 45mbar. I made this test and value never gets more than 30mbar and the test result "Sys not OK". Also, when driving very often cames fault "excessive flow" cames out with the "engine fault light" in the dashboard. Could it be that EGR valve is not perfectly working? I read about throttle body ang egr valve cleaning, but does this really helps for long time?
Ideas?
 

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The third value is the difference between the pressure reading measured when the value is closed and fully open. The second value is the MAP sensor, the difference between the two MAP readings with the valve closed and open is shown in field 3.

If the difference is too small then there may be a leak through the valve when it is closed or the valve may be faulty (e.g. stuck, not moving correctly)

I would suggest running the EGR valve adaptation. Switch off. Then repeat the test. If it still fails then there is a problem with the EGR.

http://wiki.ross-tech.com/wiki/index.php/Exhaust_Gas_Recirculation_(EGR)_Valve_Adaptation

Check the metal pipe from the valve to the throttle for any leaks. If its OK, you can take the valve off and have a look to see what the condition is.
You can try cleaning it with EGR cleaner, but technical documentation from the manufacturer of the part says that the valve should not be cleaned. They say that if it doesn't work properly then it should be replaced, cleaning would not help and can damage the valve.
As it doesn't work now, cleaning it cannot do any more harm. If it fixes the problem (re-run the adaptation after cleaning) then great, if not, you will likely need a replacement.

regards

Andrew
 
Thanks, Andrew for clear explanation!
Yes, I did this adaptation allready. It did nothing I think. I will check your suggestions and write down here results.
 
Finally outside temperature was high enough here in Latvia, so I could do some jobs on this problem. Took off the throttle body and the problem is - the egr pipe was clogged at the place where it conected to throttle body. Did some cleaning and the problem is gone for awhile :)
 
About EGR fault - more often there was fault about "not enought flow".. Dont know why there was fault about excessive flow..maybe it was only one time.
 
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