hey hey from easternshore! (with Civic VX questions)

[83gs1100g]

i have never check the valves in this. i will have to now i guess.

it stumbles at idle? could egr cause that? ive had my intake off and cleaned the egr port in the intake and the head. where else should i clean it?

[83gs1100g]

Originally Posted by xntrx

It has nothing to do with lean burn, its all rpm vtec switch over dependent.

Its technically always using 16v. At low rpm, one only opens very slightly (to promote swirl and fuel pooling), so it might as well be 12v.

Once it reaches the change over (2500 for USDM), to two rocker arms are locked together and fully open. Since you've looked at 3 stage, its the same, just without the extra high lift rocker.

If you search youtube you can find some videos.

Sounds like cheap plugs/wires, or egr.

hum... i'm just not buying this is how the vx vtec-e lean burn works. i think the vtec solinoid is active all the time sending oil to the 4th valve making it 16v mode from idle to max rpm then when your crusing and you go into lean burn when the vtec valve is disengaged to stop the oil flow to the valves creating the 3 valve setup that gives it the amsing mpg's its know for. the vtec-e in the vx is NOT for power. its for fuel economy.

not to piss anybody off here but i am truely just trying understand this system. the wiki write up is saying what was writen above. thats how it works in the 3 stage vtec.

[iveyjh]

wiki is right and xntrx is right, works just like my civic HX vtec-e except my HX switches at about 3150 rpm under light load. You can make it run 4 valve 100% by full throttle.

[83gs1100g]

ok if wiki is right than tell me what happens to the valves when it goes into lean burn? wiki says its in 12v mode from idle to 2500. if that were the case then why does it go into lean burn if its already there from idle? it only goes into lean burn when you are crusing(12v mode). all others 16v mode.

[vrmouseyd15b]

Originally Posted by 83gs1100g

ok if wiki is right than tell me what happens to the valves when it goes into lean burn? wiki says its in 12v mode from idle to 2500. if that were the case then why does it go into lean burn if its already there from idle? it only goes into lean burn when you are crusing(12v mode). all others 16v mode.

Just like my 3 stage vtec d15b. WHEN IN LEAN BURN, it is in 12v mode, first off.

THINK OF LEAN BURN AS A "GOOD LIMP MODE" - it flutters the injectors rather than spray them

With my old lx tranny, I ran as hard as 3200rpm (about 80 mph) and my econo indicator "happy light" was still on (I run a 37820-p2j-j62 ecu) ON P2J ECU'S THE ECONO LIGHT IS A SWITCHED GROUND FROM PIN A30. YOU BRING POWER TO THE OTHER SIDE OF THE BULB.



With my 3" exhaust cannon, I can hear lean burn switch into 12v mode, 1st and 2nd stages.



Lean burn sounds almost like the injectors are firing only on the positive side of a sine wave, If that makes any sense.

The exhaust sounds "waffled out" but if I push the right pedal, even below 3000rpm (when I hit first stage vtec), the sound changes to a norma lexhaust sound. Then it sounds like my normal motor

[83gs1100g]

Originally Posted by vrmouseyd15b

Just like my 3 stage vtec d15b. WHEN IN LEAN BURN, it is in 12v mode, first off.

THINK OF LEAN BURN AS A "GOOD LIMP MODE" - it flutters the injectors rather than spray them

this is correct. i understand this mode. this was a question in response to previous post.

im still trying to see who really understands how this works in the vx. cause wiki has it wrong.

[83gs1100g]

Originally Posted by iveyjh

wiki is right and xntrx is right, works just like my civic HX vtec-e except my HX switches at about 3150 rpm under light load. You can make it run 4 valve 100% by full throttle.

vx lean burn is NOT the same as hx lean burn. so tell me when does the hx go into lean burn?

[vrmouseyd15b]

essentially, my stock 2 stage jdm ecu has 4 air\fuel\spark time maps:

lean burn

12v mode (native operation)

1st stage vtec (16v mid operation)

2nd stage vtec(16v wild cam operation)



In my reading, it seems the usdm ecu's are more cut and dry in the rpm# at which lean burn or vtec is engaged, while the jdm ecu's are more flexible and seem to rely more on MAP sensor and other input to determine lean burn or vtec.

when I really get on it, and 2nd stage hits - believe me you can hear it!

[vrmouseyd15b]

Originally Posted by 83gs1100g

vx lean burn is NOT the same as hx lean burn. so tell me when does the hx go into lean burn?

I'm neither.

JDM D15B DUAL VTEC MOTOR, VX TRANNY, 4DOOR LX BODY!!

Sorry, but all my lean burn info is limited to problems I've faced in my setup. I wish I knew more, but I'm glad to share what I have

[83gs1100g]

Originally Posted by vrmouseyd15b

essentially, my stock 2 stage jdm ecu has 4 air\fuel\spark time maps:

lean burn

12v mode (native operation)

1st stage vtec (16v mid operation)

2nd stage vtec(16v wild cam operation)



In my reading, it seems the usdm ecu's are more cut and dry in the rpm# at which lean burn or vtec is engaged, while the jdm ecu's are more flexible and seem to rely more on MAP sensor and other input to determine lean burn or vtec.

when I really get on it, and 2nd stage hits - believe me you can hear it!

ok but what does this have to do with vx vtec-e operation?