winterheating wrote: pusd wrote:
My current theory on why many Mk7's run worse after blanking is that the EGR valve on the Mk7's ....
Strange, mine runs better when disconnected!
A smoother & stronger pull from lower revs. The van's now happy pulling away from 30mph and below in 4th and feels quite nippy with it whereas before (EGR connected) it feels a bit strangled until about 2k, when you get a sudden surge.
its maybe because your EGR isnt working proparly thats why your getting hessitation so disconnecting is going to make it better,
but if EGR is working correctly PCM can use that to its advantage so when like Martyn says on a van with no problems disconnecting EGR makes it run worse.
read somewhere that modern engines use the reduced combustion temps, caused by EGR, to actually improve power, by adjusting timing correctly.
so maybe the MK7s need the EGR to be functioning 100% correctly to get the full potential.
but also the Map sensor could affect correct operation of EGR.
is there any MK6's where the MAP is after EGR
entry cos TIS says that in some situations the MAP is used to monitor the EGR
WH, I have no reason to suspect that the EGR on my van is working anything other than perfectly - at 6000 miles, power delivery is no different to when it the van was new.
But the van is certainly much better at lower engine revs (<1800) with the EGR disconnected.
I don't know much about making engines meet various emissions regs, combustion temps or adjusting timing for an EGR etc, but I do feel that it is fundamentally wrong to put exhaust gases back into an engine!!!
Look at all the problems on this site alone from failing EGR's (poor running, smokey, lack of power & increased fuel consumption...).
Friends with other brands' of vehicles have had problems too.
.... Then take a look in an intake manifold from a reasonably well used vehicle and marvel at how the thing can still run ok with all the build up of sludge in there from the layers of soot & carbon.
This is why I am (obsessed?) trying to find the most effective way of stopping the flow of exhaust gases into the engine - currently it looks like I have to live with the EM light displayed though!
Of course any feedback is good!