Year of Manufacture *: 2006 Onwards.
I read in an earlier post that the VAG FSI engines do not run stratified lean burn in the UK because of fuel quality. Is this true and if so, what is the problem, is it the octane rating or to do with something in the fuel or maybe emissions related?
I did hear some early LPG systems specifically designed for direct injection engines in the UK were only suitable for non lean burn, therefore stratified fueling must have been in use at some time.
We recently purchased a BMW 5 Series 525i fitted with the 3.0 litre 6 cylinder N53 lean burn direct injection engine installed with Piezo injectors, this vehicle is being used as a test mule. I have already started analyzing how the 4 different stages of fueling operate using our rolling road, a 4-gas analyser and 4 channel lab scope, some readings contradict the vehicles live data.
If fuel quality in the UK is a problem to VAG then why is it not a problem to BMW, might it be that their engines run on a lower compression ratio? I am aware of some of the Piezo injector and high pressure pump problems BMW are having often being blamed by their owners for the engines misfiring and cutting out. These engines have a compression ratio of about 12:1 so surely they should be run on a high octane fuel such as Shell V-Max?
Could it be that some vehicle manufacturers originally released vehicles into the UK running lean burn but following customer complaints recalled them and re-flashed their ECU's to run homogeonous lambda 1 without even informing Main Dealers?
Any information regarding any make and model of direct injection engines and ongoing problems and fixes would be much appreciated.
Regards Eddie Zyla.
Technical Director
CRD Performance.
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