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

I know from the previous email exchange that the owner experienced misfire in the past and the IG coil at #2 cyl was replaced.
Looked like the spark plugs were not replaced and kept using the same ones even there were brown rust markings and white corrosion build up on the insulator body on one of them.




Also, the one at #2 cyl (looked like it was previously in #1 cyl based on the big text) looked as if it was dropped in the past as the metal edge was flattened.
All six plugs looked to be having bit extra carbon all round. May be sign of idle hunching....

Not sure whether these were the origianl ones from the factory or not but based on above facts and considering the mileage, decided to replace all six this time.
Of course, using the proper OBD2 spec PFR6L-11 and not the PFR6G-11.

By the way, the original ones were tightened with way too much torque. At first, I couldn't even move them slightly.
Another reason why I always remove them while they are cold as I have no idea on the condition.
#4 showed some oil around the threaded body but couldn't see wet marking at the base of the plug hole.




Considering the hunching idle and never cleaned the intake air temperature sensor on this engine, decided to clean it at the same time.
I need to reset the ECU any way after taking the compression.
It was covered in lots of oil with some sort of solid oil gunk but not too bad compared to other engines.
Will carry out 70mph cruising mode during the test driving session to check the closed loop fuel control.




Very strong and small deviation between the cyl with the compression check result.
Full data has been sent to the owner over email.

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



Time to overhaul the brake caliper and bracket.

[Edit: To the owner]
Please check the fuel cap everytime when you refuel the car.
While releasing the fuel pressure before removing the fuel filter, it felt very heavy in removing the cap.
It was like cross-threaded bolt.
There was no obvious damages to the cap thread but when you try to tighten it, it can start making clicking sound indicating that the cap is tight when it is not fully locked/closed yet.
You need to press in a little while turning it to make sure it is properly closed.
I will try my cap on your NSX later to confirm whether it's the cap issue or the filler neck related.



More to follow later.
Kaz