14-08-2012, 08:19 AM
Check the coolant temperature sensor...
Yes, the MAF detects the air temperature into the engine, however, there's 3 coolant temperature sensors on a HDi, and there is a map to relate coolant temperature to IQ and SOI IIRC the blue or green one should be the one to the ECU IIRC. Brown is Bitron unit.
It could be sensing wrong and assuming the engine is hot all the time and running more retarded timing, causing the lumpy running.
Yes, the MAF detects the air temperature into the engine, however, there's 3 coolant temperature sensors on a HDi, and there is a map to relate coolant temperature to IQ and SOI IIRC the blue or green one should be the one to the ECU IIRC. Brown is Bitron unit.
It could be sensing wrong and assuming the engine is hot all the time and running more retarded timing, causing the lumpy running.
