OK, I know you can raise the fuel-cut level by putting a bleed valve in the MAP line, but by raising it this way you are basically fooling the ECU into thinking there is less boost than there actually is, right? So surely the ECU can't provide the correct fuelling, because it's seeing less boost than there actually is? Or am I talking bollox?

 

According to studies by John Banks, the MAP sensor don't effect fuelling.

 

So how does the ECU adjust fuelling relative to boost pressure?

 

MAF sensor is the key there.

 

So what use is the MAP sensor??
IIRC it is used in the absense of a MAF sensor on link set ups but apart from fuel cut what purpose does it serve on normal ECU cars??
Thanks
Rob

 

Closed loop boost control, atmospheric pressure compensation, limp home mode if MAF fails.

 

John, does the MAP sensor have any influence on ignition at all ? Or is that MAF/RPM/TPS based as well ?

 

So how does the ECU enrich the mixture relative to boost pressure, if it doesn't use the MAP sensor???

 

MAF sensor.

 

Things appeared to be different with STI v.5&6 engine management

 

Katana, are you sure ?

 

Can't see any effect on ignition from MAP on MY99/00 UK and STi.