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

Tow hook cover was missing from the front bumper so new colour coded one
ordered and installed.
Hope it will stay there for longer this time.
Most of the time, it will come off if the bumper was re-sprayed or with the age
and heat, the rate of warping between the bumper and the hook cover is different
resulting in cover falling off.




After heat cycling the engine many times, finally I was happy to bring the
Eng to the operating temperature and check the idle rpm.

EACV disconnected and aimed at 600rpm.
CEL is the result of disconnecting it.
The dash gauge is not accurate enough for this as quite often,
it will show higher figure.


I only had to open the idle adjust screw about 35deg from its original position and
locked it with the liquid gasket later.

If you can’t keep the engine running at 600rpm,
then you better wash your TH body.




Carried out the Eng block test.

In the past, the test fluid changed into yellow on this engine due to what we saw
on the head gasket.
At that time, the coolant temperature gauge stayed fine under normal street
driving condition but when driven hard, the coolant escaped from the overflow
tube of the header tank and with low coolant level, it made the situation even worse
and the gauge slowly climbed up.

Not sure about the initial cause but possibly the cooling system was not serviced
properly in the past.
The old WP was leaking the coolant from the seal and also from the seepage pipe so
that didn’t help.

Another reason why you should replace the WP at every TB service regardless of
the mileage covered.

After the head gasket service, there was not even a hint of yellow and the
test fluid stayed as blue so I’m happy with the result.




Time for the compression check.

I normally use average data of 2, 3 rounds but on this occasion,
I had to carry out extra round because the data looked to good to be true
especially after what I saw with the cold leak down test.

The full data was already sent to the owner through the email.

[psi]
#1: **8, #2: **8, #3: **5, #4: **0, #5: **1, #6: **1

All six cyl were very close each other with very small deviation window and
even the #6 cyl that was more than 20psi lower than the max figure long time ago
showed the same figure as #5 cyl so really happy with the result of the Eng Refresh.


Once again, it proved that it’s better not to touch the valve clearance unless
you see the big changes in the compression even it is specified as one of the
Honda service menu for UK NSX.

In Japan, it’s not part of the service schedule and I won’t touch it until the
next TB service.
If adjusted properly and the engine looked after well until the next TB service,
I never saw noticeable change in compression even after 60K miles on NSX engine.



New spark plug with correct heat rating.
With just multiple eng fire up without even touching the TH pedal,
it doesn’t provide much information but even so, it’s nice to see clean terminal
on all six cyl even after going through the worst condition of multiple fire up with
only mid temperature and running the eng with EACV disconnected.




For MT model, I don’t re-install the Eng bay cooling fan.
In fact, Honda removed it from later MT model and this is the standard procedure
among NSX specialist in Japan where the hot and humid summer can reach
continuously close to 40deg and from time to time, it will even exceed it.

No point in keeping it at my place so I just return it to the owner.