hey hey from easternshore! (with Civic VX questions)
 

hi all been a lurker here off and on for years. i got the bug 5 yrs ago when gas started to climb and i owned a 99 f150 and 00 4x4 expedition. sold those quick when they said gas was going to be 4$ a gal. i got a 05 prius for her an a 92 vx for me. and i get better mpg's than she does! ha!

anyways im posting to ask some techno questions about my vx and can someone tell me how vtec-e works? i thought the vx vtec-e worked in 16v mode all the time until it goes to lean burn then it goes to 12v mode?

and my vx has a miss at idle and i think that miss carries over when in lean burn. i have new 02, dist, copper plugs, wires, injectors. no cel. she runs perfect otherwise. still gets 55mpgs. i just think if i fix the miss she will get better mpgs? it only has the miss when fully warmed up so not sure what difference that makes?

Welcome to the site!

I'm no VX expert, but they'll be here to help out shortly.

I can't help with the valve question, but on the miss I would suspect the ignition coil in the distributor. Because you say it only happens when the car is warmed-up. That suggests expansion of the coil expanding to a problem point under the heat. Could also be the ignition control unit in the distributor. I replaced my distributor with an Autozone unit and got a warranty and solved a similar problem. Hope that helps.

thks for the help guys. its got a new dist already? this is my dilemma? i was thinking tps or ecu?

Welcome from Baltimore.

sup neighbor!

is there a specific dist needed for the vx? i got a aftermarket one off ebay.

also i know from factory it comes with a brushless alternator? is this neccessary?

so who is the vtec-e experts out there? i ask this cuse i think the description is wrong in wiki. i was sure the vx works in 16v mode all the time until you go in lean burn then goes to 12v mode. can anyone confirm this? i think what someone put in wiki is mixing up the 3 stage vtec mode that it runs in 12v mode all the time below 2750 rpms.

wikipedia.org/wiki/VTEC#VTEC-E]VTEC

Lean stumble warm? Could be a lot of things. I would check the valve clearance, just to make sure it's right. Could be EGR related, but if you're getting 55 MPG it must not be anything too serious. More obvious when warm, probably EGR related, they need the system cleaned if that has not been done.

regards
Mech

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.

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?

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.

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.

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.

http://rs1291.pbsrc.com/albums/b551/...0?t=1403052108

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

http://rs1291.pbsrc.com/albums/b551/...cb.jpg~320x480

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:D

http://rs1291.pbsrc.com/albums/b551/...1c.jpg~320x480

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.

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

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)

http://rs1291.pbsrc.com/albums/b551/...0?t=1403053774

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!

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:thumbup:

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

vtec e is equivalent to my 12v operation

from there your ecu can lean burn for more economy, or go into vtec for 16v

what is?

[/QUOTE] Its technically always using 16v. [/QUOTE]

correct. and thats at any rpm that its not in lean burn.

[/QUOTE] At low rpm, one only opens very slightly (to promote swirl and fuel pooling), so it might as well be 12v. [/QUOTE]

yes but not at all low rpm. it only does this if you are easy on the throttle. as soon as you step on it even at 1500rpm it goes back to 16v mode.

[/QUOTE] 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. [/QUOTE]

its in 16v mode even at idle. vx vtec-e doesnt have to wait to get above a certain rpm to go in 16v mode. the rpm limit just means it wont go into lean burn after that point.

lean burn and vtec, they are independant. Don't get stuck thinking they are connected. You can lean burn even after the change over if the load is low enough.

To clarify:
Lean burn = any time it is low load (assuming gear or temp is within spec).
Vtec (full 16v) = anytime over 2500rpm in US spec d15z1's

Notice from the above, there are 4 possible combinations, since the requirements for each are different.

[QUOTE=83gs1100g;430318]what is?


HUH??? Ok, my turn to ask you some questions.

Since we are all ECOMODDERS, we do things to our cars. Many times this means switching motors, transmissions, etc. I'M NOT SAYING YOU DID, BUT....

If you told us what engine block, head, and ECU you are running, you would be able to cast a much wider net in your search for information.

Then you might really find an expert, a guy that might not have a clue what motor came in YOUR car, but because he liked the specs and bought the same motor to put in HIS car, he would know what you're talking about:thumbup:

I'M NO EXPERT, I'm just trying to share what I picked up along my quest for knowledge:D

http://rs1291.pbsrc.com/albums/b551/...e7.png~320x480

[QUOTE=vrmouseyd15b;430321]bone stock vx. all original. i am trying to find a vx service manual if there is such a thing?

are you saying vx vtec-e is same as hx vtec-e? cause there not from what i have learned.

If I remember, correctly, I found a download link at < d series.org >

Let me see if I can find it again and post a link - it's too big to share otherwise

my book only shows hx, not vx. sorry.

what is that car called? ek? eg? em? eh?

I've got an idea...

i found it here - hondatech.info: Honda service manuals

92 civic vx

Thanks, I've been looking for that one! You have the d15z1 motor. I've got one in my garage waiting to be built!
http://i1291.photobucket.com/albums/...psb19896c2.jpg

rebuild? why? what are you going to use it for? mine has 290k on it and still gets 55 mpg and no oil burning. i recently took a 2000 mile trip with a motor in the back and had not a ONE problem!

This one will be 1.5 liters of fury! remote turbo (low boost), lean burn, and those rediculously long vx gears so I can ride boost for more than 1 second before I have to shift!

It's nowhere near ready, I don't even have the car it will go in yet (I'm thinking Integra or accord, 2 door with leather, sunroof, etc) It's going to be a project either way!!!

I brought the z1 home from PA, along with the vx tranny I'm currently running (about 950 miles each way from home) and brought the tranny and motor home in my "V"LX civic!

http://rs1291.pbsrc.com/albums/b551/...0?t=1403067859