"té_qui" wrote:

Some service manuals call it a spool valve, other a solenoid valve, I
guess spool valve is a poor translation from Japanese, a solenoid is, in
effect, a spool of wire. I'll refer to at is the VTEC Solenoid Valve

The VTEC Solenoid Valve is always grounded, it is turned on by applying
voltage to the single pin connector. The service manual is somewhat
confused on the issue, in the wiring diagram it shows the wire from the
ECU to the VTEC Solenoid valve being ORN/WHT. It then connects to the
engine wire harness where it changes color to GRN/YEL. Now, in the
troubleshooting section it say to apply battery voltage to the GRN/WHT
terminal to open up the VTEC Solenoid valve. My interpretation is that
you should remove the 1-pin connector from the VTEC Solenoid Valve and
apply battery voltage directly to the pin on valve.

I would be cautious about this. Under normal operation, VTEC will not
engage unless the engine is warm and the oil pressure is sufficient. I
would pull a wire from the VTEC Solenoid valve into the cabin and either
have lighter plug type connector on it or some sort of switch to +12V.
That way you can engage it while driving and make sure the engine is
warmed up before doing so.

Sounds to me like VTEC is slow to disengage in your engine. I don't know
if there is a port to release oil pressure when VTEC is disengaging, or
if it is just expected to leak down. In either case, If you are close to
doing an oil change, you could try using the thinnest oil recommended
for your engine (or even spring for a full synthetic) and see if it
helps.

té_qui wrote:

3k is /way/ too low for the vtec cam.  fixed cams are a compromise based
on extensive research to map an engine's volumetric efficiency.  having
two sets of cams [vtec] allows a broader effective power band [two bands
with an area of overlap between them].  the lower cam set works well up
to 5k and is relatively torquey.  the vtec is much more powerful /at
high revs/ but lacks low end and is narrower.  on real high tune
engines, the power band can be as little as 1k rpm.  trying to stick
with the majority of rpms on the vtec cam achieves nothing but emissions
problems and premature wear of the cam.  notice how there's two sets of
lobes for the low rev cam profile and only one for the vtec?  that means
greater load bearing area and therefore lower wear rate for the region
in which a road engine spends the majority of its life.

bottom line - if this car's a daily driver, don't monkey with the vtec.
 anything below 4k is absolutely pointless.  if you want this car for
the track, don't bother with the vtec at all - you shouldn't be pulling
at much less than 6k anywhere on the circuit so you may as well just go
straight to a single profile cam with a high rev power band.