Quote:
Originally Posted by Chrysler kid
You're reading voltage under 1v aat the secondary oxygen sensor to determine lean burn correct?
As far as 3 valve operation on the y5 I have no idea, the upshift light could be saying when the car is out of 3v operation for all I know. Vtec engages when the car is in 4v (16v) mode and opens the valves at a more agressive duration than normal.a
Vtec on the hx is triggered at a higher rpm than the ex model, and I do know the vx would use 3v mode in all gears but honda received complaints about the abrupt change from 3v into 4v into vtec. So I assume 3v mode in the hx is only in lean burn conditions to make the car more friendly to drive in lower gears
I spent a few nights reading up about the man who engineered "lean burn" but I can not recall any spefic functions or features besides creating a swirling effect by only using 1 intake valve allowing the 2 exhaust valve to release the heated exhaust much more effeciently allowing the car to run leaner without the negative side effects of added heat and strain on the valve train
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Yes I am watching my rear o2 but I can easily tell without it.
The upshift light definitely has no correlation to 12or 16 valve mode.
I think you are confused about the HX vtec. I can dig up some good info on the cam profiles if you'd like.
It's in 12 valve mode until the Vtec solenoid engages then it's 16 valve mode.
This cross over happens at a MUCH lower RPM than the performance orientated Vtec *EX*.
I can clearly feel mine happen right aroudn 2900 rpm's if i'm heavy on the throttle.
If anyone is interested I will hook a light to it and watch exactly how it behaves.
My hunch is it stays in 12v mode almost all the time and only goes 16v when under acceleration.