Opening VTEC....

[arrowhead]

i have an inquiry. i had this problem before and it was solved with a re-chipped ecu. however i notice something and would just like to know if its normal.

B16A motor. i know the oem ecu has a safety feature where the temperature of the engine has to be at the mid point, in order for the variable valve to work, correct?

so i have this ecu, that removes that safety feature because with my previous ecu, it was very difficult for me to engage my vtec.

i notice this: first few attempts, the vtec sound is rather soft, or rather, hardly noticeable. i have to rev it a few times (maybe 3-4 times) only then will i hear the vtec screaming like it should. is this normal? or do i have a problem with my vtec?

 

[pencalat]

i have an inquiry. i had this problem before and it was solved with a re-chipped ecu. however i notice something and would just like to know if its normal.

B16A motor. i know the oem ecu has a safety feature where the temperature of the engine has to be at the mid point, in order for the variable valve to work, correct?

:wavey:THAT'S CORRECT... IF STILL COLD THE VARIABLE VALVE WILL NOT OPEN..

so i have this ecu, that removes that safety feature because with my previous ecu, it was very difficult for me to engage my vtec.

i notice this: first few attempts, the vtec sound is rather soft, or rather, hardly noticeable. i have to rev it a few times (maybe 3-4 times) only then will i hear the vtec screaming like it should. is this normal? or do i have a problem with my vtec?

UR RECHIPPED ECU MADE UR VTEC ENGAGE AT WHAT RPM?? IS IT 5.2K??
IF SO... IT'S NORMAL COZ OPEN TO EARLY THAN USUAL AT RPM 5.8K..

 

[arrowhead]

it used to be at 5.5k, but suhaimi from avantech did some minor tuning to it, now it opens back at 5.8k... however my question was regarding the soft vtec sound on initial attempts... :hmmmm:

 

[crower75]

it used to be at 5.5k, but suhaimi from avantech did some minor tuning to it, now it opens back at 5.8k... however my question was regarding the soft vtec sound on initial attempts... :hmmmm:

if it's from "suhaimi" (eeuuuuwwwww.....we call him mie or cempiang) it's like dat one hahahhahaha (joking only la hehe)

maybe your VTEC malu2 kucing at first....after awhile it starts to make noise. On a serious note, it's true la, if the car temperature is not at the optimum level yet, VTEC won't engage.

 

[arrowhead]

malu malu kucing? WTF LOL. vtec was supposed to be furious, now malu malu kucing pulak LOL... cannot make it laaaa..

 

[budin99]

if it's from "suhaimi" (eeuuuuwwwww.....we call him mie or cempiang) it's like dat one hahahhahaha (joking only la hehe)

maybe your VTEC malu2 kucing at first....after awhile it starts to make noise. On a serious note, it's true la, if the car temperature is not at the optimum level yet, VTEC won't engage.

quite long time no see..see taim no long haven't see abam crower posting here keh keh keh..

p/s- Very easy..bring back to avantech to check :D

 

[arrowhead]

haha, here's the catch. when i reach avantech, my vtec functions perfectly.... cuz my hse to avantech is like 20 minutes..

aih.. :hmmmm:

 

[pencalat]

Hehe.. that mean ur sickness car scared la when reach the clinic avantech...

 

[crower75]

quite long time no see..see taim no long haven't see abam crower posting here keh keh keh..

p/s- Very easy..bring back to avantech to check :D

Low profile (but not using low profile tyres)

Waaa so good aaa avantek nowdays ? Every car forum I go got mention avantek dis avantek dat tek dis tek dat tek dis tek dat hahahahha so long as not tetek ok la hor ? Like dis Fei Lou oso must retire oredi hahahha

 

[arrowhead]

who is fei lou? kasi intro sikit. haha the more the merrier...

actually my question is only, normal kah the vtec sound soft for the initial stages?

 

[shiroitenshi]

I think instead of the temp sensor, another reason why the vtec cannot engage is because of the green pressure sensor below the solenoid. VTEC runs on oil pressure, so if your engine is suffering from low oil pressure, then the vtec will work intermittently, and sometimes, only when the oil is thin at higher temperatures, then the pressure will build properly and vtec engages correctly.. that why you should wait till the engine is cold and see if the problem is repeatable each time the engine is still cold.

 

[arrowhead]

u got PM shiro sifu.

 

[D-IV]

Check your solenoid as well, its spring operated. Sometimes sludges get in there and can cause it to be stuck too. Take out the VTEC solenoid and clean it out. Hardly the problem though, my first impression would be like Shiro's, might be the oil pressure sensor acting up..

Once the water temp passes 60, VTEC will open. I'm not so sure whether there is such thing as partial opening of VTEC.

 

[arrowhead]

ahh yes D-IV sifu has spoken. as far as the solenoid is concerned, i've serviced it before this. not long ago, maybe 3-4 months ago. and also, i just changed my solenoid seal weeks back.. so worth a check though..

hmmm i'll get eric of avantgarde to check my oil pressure sensor tmr.. any heads up on how to check it?

as far as partial vtec opening, my really sounds like it... haha its like 50% of how the vtec should sound...

 

[udengfahlawi]

i've encountered several frens with similar case before, the vtec sound not garang....but i think as long as the power is there, doesnt matter about the sound so much laa....if no (or lack) vtec sound plus can feel no power (butt dyno), then really hafta check thoroughly....nevertheless, do check all the things recommended by others (vtec solenoid, etc.) just to b sure it is not an impending disaster to come.....

 

[fobs]

abe crower, u still up north kah? when wanna bring ur EG to test test with penang adik adik,...?

eh,... 60degrees? i think my engine normal operating temp is 80,... rite???

 

[D-IV]

VTEC is triggered by several factors i.e. oil pressure, water temperature, vehicle speed etc... that i think is known already by people.

Nyway Fobs, normal operating temp and water temp to trigger VTEC is different. It was just on top of my head on the 60 degrees, maybe 40-60 degrees, can't remember too well. In terms of normal operating temp, i see anywhere around 80-83 degrees on hot days cruise to work. Maybe 75-78 during the nights cruise.

 

[arrowhead]

vehicle speed? erm, at what speed will it NOT open?

 

[shiroitenshi]

Like DIV said, VTEC usually either works, or it doesn't. I'm not sure what you mean by soft vtec sound.

Sorry, but I totally forgot to ask the most basic question, arrowhead... when was the last time you changed/serviced your oil pump? If never, then it'll probably goes as follows.

Your current situation, probably best if can test by swapping the green pres. sensor, testing the car again from a cold start (means you wait for engine to cool, then start it, warm it up, then drive and see if VTEC engages properly)

If not, then it's time to check your oil pressure. This one a lil more expensive, and perhaps not, if you already have the oil pressure meter in your car, in which case, it's a simple matter of relocating the sensor (oil pres. sender unit) to check the pressure at the oil pres hole (green plug place). I'm not sure if the plug fit, but in my case, I conveniently used the sender unit on the VTEC hole where people usually use for external VTEC line, and blocked off one end of the T fitting with a bolt. That car is B20, but with internal VTEC passage, not external.

I have experienced before, where a guy with a chipped ECU with all sensors related to vtec disabled, has a vtec that 'jumps' in and out of VTEC. Seems like his oil passages are so clogged, his oil pressure was on the low side.. or so I initially thought.

Before that though time to check everything out first, tried plugged in a stock ECU, and even when the temp is warmed up, the VTEC wouldn't engage... at all... swapped temp sensor & oil pres, no go either... so finally tried plugging in an oil pres sensor from his Defi (see above), and it read about 36-38psi, below minimum for VTEC operation, cleaned solenoid and the oil passage in the head (obviously have to REMOVE the head) and it works okay again, for a while... in the end, had to change the oil pump.. no problems since.

About the vtec being soft..
I don't recall his vtec being softer or whatever.. it's just that it simply lags before opening vtec, because the oil pressure was not sufficient until higher up in the rpm. Sometimes after just opening, it also jumps out of vtec.

So not sure if any of this would even be related to your problem.

 

[shiroitenshi]

VTEC temp, I'm not sure stock, but I think it's about 50-ish, so DIV is close.. for hondata, I set mine to 65, because I know I won't rev the car when it's cold.

From my point of view, the reason why the temp is there is because of valve lash.

Remember when setting the cams? Why do we need to wait for the head to be cold? so the measurements aren't affected by the heat.

Similar to when the engine is in use, cold means that the cam lobes and the cam followers aren't really taking up the slack of the valve lash?

What happens when valve lash is too loose?

What happens when valve lash is too tight?

That, people, is a good question to ask your mech.