VX California to 49state Conversion help

[TomO]

The wire that runs to the VTEC-E solenoid is grounded internally by the ECU when it engages VTEC-E. I use an LED with a switched 12+ and then the ground is connected to the VTEC-E wire, when VTEC-E engages (2500+ RPM and more than 50% TPS) then the LED will light up. VTEC-E operates independently of Lean Burn.

Yes, CivicVX.com used to be my website devotes solely to the VX, but due to a hosting disagreement, I only have the rights to the domain name now, and no longer have any content there.

[oldertech]

Ok, now I'm a bit confused. The vtec solenoid doesn't operate at the same time as leanburn? I was under the impress that the engine had to go from 16 to 12 valves to let the condition be right for the leanburn. My thinking was that if I monitor the solenoid that I would know when leanburn was happening. But is there some other sequence that I'm missing?

I can feel leanburn kicking in and out, and when I'm in second gear to slow down for a toll gate, I put on the gas and it feels like afterburners kick in at 2500 rpm or so. Are these separate processes?

In the California version, does the vtec kick in and out at 2500 rpm?

Scott

[TomO]

You are correct that Lean Burn works when the motor is in 12Valve mode, which is when the VTEC-E is NOT engaged. at 2500RPM and above that certain throttle threshold, the ECU grounds the VTEC solenoid and then fully opens all 16 Valves, Lean burn does not happen when VTEC-E is engaged, mostly because the combustion dynamics turn to a tumble type system which doesn't support a lean mixture. When VTEC-E is not engaged, the vehicle is in 12 Valve mode where both exhaust valves are opening normally but only one of the intake valves are opening normally. The other intake valve is only opening enough to release any fuel that is sitting on top of it. This makes the fuel mixture swirl inside the combustion chamber. That makes it easier to ignite a lean mixture.

So, basically, Lean burn is dependent on throttle position, engine temp, and engine load below 2500RPM, but once VTEC-E engages, there is no Lean Burn.

SVOboy would be able to verify if Lean Burn is available above 2500RPM as he has had his motor in Lean Burn up to 70mph I believe. But the circumstances for that would be a light engine load and very small <10% throttle position. That is one way that you can go above 2500RPM and still have Lean Burn. VTEC-E will not engage until 3000RPM then as the driver is not demanding the full power of the motor.

Hope this clears some things up.

[oldertech]

TomO,

Clears things up beautifully. Leanburn and vtec have a different relationship than I had first understood. So if one were to monitor the system to have a green "Eco" light, it would have to read injector pulse timings to activate the light. Right?

[TomO]

Originally Posted by oldertech

TomO,

Clears things up beautifully. Leanburn and vtec have a different relationship than I had first understood. So if one were to monitor the system to have a green "Eco" light, it would have to read injector pulse timings to activate the light. Right?

Glad that helped to clear things up.

To monitor Lean Burn on the VX, you can simply get the voltage monitor kit from Autospeed magazine and set it to the range of the OEM wideband to get a reading. You can even use just one of the LEDs from the readout so you would have an "Eco" light.

here's the how-to from Autospeed: Monitoring Factory Wideband