Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

From time to time, I was asked about the misfire/hesitation issue
and after checking the obvious things such as the spark plug, IG coil,
O2 sensor, etc, one of the thing to be checked is the fuel supply.

On the ECU software, there is no fuel pressure related adjustment
for the fuel timer calculation so ECU assumes that the fuel pressure is
always at the correct regulated level which is about
343kPa (3.5kgf/cm2) above the intake manifold pressure.








So, other factors such as rpm and altitude will affect the
absolute reading but at about idle rpm, you will see about
350kPa (324 – 363 kPa as in the manual) while the
intake manifold pressure tube is disconnected from
the pressure regulator.









With the tube connected back to the pressure regulator,
it will be around 250 – 304 kPa depending on other factors.


It is not that common to have fuel pump failure on
Japan or UK based NSX even with high mileage but
you can find fair amount of failure reports through
NSX Prime including the NSX based in US and
also part of Europe.

Not sure whether it is something to do with the
fuel stability especially the amount of ethanol or not.

Addition to the compression check, checking the fuel pressure
once a year may detect early sign of certain issues.


Monitoring the fuel pressure is very important especially
if you have FI application so I know some owners installed
the gauge on top of the fuel filter.


Kaz