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5th gear open vtec no acceleration.

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ethene
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5th gear open vtec no acceleration.

Post by ethene » Tue Nov 22, 2011 3:24 am

Hi guys, what could be the problem when I accelerate hard (already floored the accelerator) when on 5th gear, just when vtec was about to kick in, engine suddenly no power and cannot accelerate anymore.

I let go and accelerate again. Same thing happen when vtec was about to kick in.

No problem with vtec from 1st to 4th gear. Only 5th gear got such problem...

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Re: 5th gear open vtec no acceleration.

Post by Will_SG » Tue Nov 22, 2011 7:47 am

ethene wrote: I let go and accelerate again. Same thing happen when vtec was about to kick in.

No problem with vtec from 1st to 4th gear. Only 5th gear got such problem...
Is it the same when u in 4th with VTEC engaged and shift to 5th gear at maybe about 7000rpm?

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Re: 5th gear open vtec no acceleration.

Post by ethene » Tue Nov 22, 2011 11:48 am

Will_SG wrote:
ethene wrote: I let go and accelerate again. Same thing happen when vtec was about to kick in.

No problem with vtec from 1st to 4th gear. Only 5th gear got such problem...
Is it the same when u in 4th with VTEC engaged and shift to 5th gear at maybe about 7000rpm?
Nope only 5th gear.... Ive did some research and it seems like a clutch slip...

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Chasers Verna
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Post by Chasers Verna » Tue Nov 22, 2011 11:59 am

clutch slip would not just show up in 5th gear, it will appear in all gears. in fact, clutch slip usually shows up when alot of torque is used, so lower in the rev range, and often when first accelerating or going up a slope. once you are up and running in 5th gear 5000rpm, not likely. (unless your vtec kick is sibeh fierce!)

based on my personal experience and understanding. correct me if im wrong.

do your revs keep rising in 5th when vtec opens, or do they stop rising? has it always been like that or just recently?

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Re: 5th gear open vtec no acceleration.

Post by Will_SG » Tue Nov 22, 2011 8:16 pm

ethene wrote:
Will_SG wrote:
ethene wrote: I let go and accelerate again. Same thing happen when vtec was about to kick in.

No problem with vtec from 1st to 4th gear. Only 5th gear got such problem...
Is it the same when u in 4th with VTEC engaged and shift to 5th gear at maybe about 7000rpm?
Nope only 5th gear.... Ive did some research and it seems like a clutch slip...
so u mean when 4th gear (VTEC engaged) up shift to 5th Gear at above VTEC rpm, the VTEC remains engaged. The symptoms only appear when trying to accelerate in 5th up to VTEC rpm.

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Post by ah_rek » Wed Nov 23, 2011 11:47 am

5th gear vtec ?

bro you are running too fast..
Image

slow is gold.

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Post by flava » Wed Nov 23, 2011 7:53 pm

if got close ratio and high FD shd be easy to hit vtec in 5th gear??
"hi bro, your items can cheaper bro??"

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Re: 5th gear open vtec no acceleration.

Post by r3nnylim » Fri Nov 25, 2011 9:30 am

ethene wrote:Hi guys, what could be the problem when I accelerate hard (already floored the accelerator) when on 5th gear, just when vtec was about to kick in, engine suddenly no power and cannot accelerate anymore.

I let go and accelerate again. Same thing happen when vtec was about to kick in.

No problem with vtec from 1st to 4th gear. Only 5th gear got such problem...
what setup is your engine? ecu running on?
It's when the VTEC roars there ain't no turning back.

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Post by ethene » Sun Nov 27, 2011 2:24 pm

Everything stock. ECU stock. ok i give a better description.

no matter how hard i rev, all the gears all totally ok. only lets say when my speed is 100km/h and im on 5th gear, and i continue to accelerate... just when rpm was about to hit 4-5K or so (just before vtec open) then suddenly no accelerate, rpm drop to idling rpm. cannot accelerate anymore even when i step more.

so i release my foot, and rpm and speed drop. then i step again, can accelerate, but near 4-5 k rpm same thing happen again.

I try to take a video to show a better picture.

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Post by Will_SG » Mon Nov 28, 2011 12:16 am

ethene wrote:Everything stock. ECU stock. ok i give a better description.

no matter how hard i rev, all the gears all totally ok. only lets say when my speed is 100km/h and im on 5th gear, and i continue to accelerate... just when rpm was about to hit 4-5K or so (just before vtec open) then suddenly no accelerate, rpm drop to idling rpm. cannot accelerate anymore even when i step more.

so i release my foot, and rpm and speed drop. then i step again, can accelerate, but near 4-5 k rpm same thing happen again.

I try to take a video to show a better picture.
May want to try to swap ECU to try.
As far as I know for VTEC to engage need to fulfill 3 inputs:
1) RPM
2) Speed
3) Throttle position

Since u mentioned that the rpm can drop to idling rpm, I suppose u r driving a auto gear box?

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Post by ethene » Mon Nov 28, 2011 8:12 am

Will_SG wrote:
ethene wrote:Everything stock. ECU stock. ok i give a better description.

no matter how hard i rev, all the gears all totally ok. only lets say when my speed is 100km/h and im on 5th gear, and i continue to accelerate... just when rpm was about to hit 4-5K or so (just before vtec open) then suddenly no accelerate, rpm drop to idling rpm. cannot accelerate anymore even when i step more.

so i release my foot, and rpm and speed drop. then i step again, can accelerate, but near 4-5 k rpm same thing happen again.

I try to take a video to show a better picture.
May want to try to swap ECU to try.
As far as I know for VTEC to engage need to fulfill 3 inputs:
1) RPM
2) Speed
3) Throttle position

Since u mentioned that the rpm can drop to idling rpm, I suppose u r driving a auto gear box?

Nope on manual... Tried to take video yesterday night but the problem is gone. It's like on and off... zzz

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Post by Will_SG » Mon Nov 28, 2011 9:57 am

ethene wrote:
Will_SG wrote:
ethene wrote:Everything stock. ECU stock. ok i give a better description.

no matter how hard i rev, all the gears all totally ok. only lets say when my speed is 100km/h and im on 5th gear, and i continue to accelerate... just when rpm was about to hit 4-5K or so (just before vtec open) then suddenly no accelerate, rpm drop to idling rpm. cannot accelerate anymore even when i step more.

so i release my foot, and rpm and speed drop. then i step again, can accelerate, but near 4-5 k rpm same thing happen again.

I try to take a video to show a better picture.
May want to try to swap ECU to try.
As far as I know for VTEC to engage need to fulfill 3 inputs:
1) RPM
2) Speed
3) Throttle position

Since u mentioned that the rpm can drop to idling rpm, I suppose u r driving a auto gear box?

Nope on manual... Tried to take video yesterday night but the problem is gone. It's like on and off... zzz
Bro, For manual, with your gear engaged at 5th gear, it shouldnt be able to drop to idling rpm even if VTEC cant engage. It is as if your gearbox isnt engaged. Forget about my advise on ECU, u may need to check your gearbox.

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Post by uraco » Mon Nov 28, 2011 3:56 pm

Will_SG wrote:
ethene wrote:
Will_SG wrote: May want to try to swap ECU to try.
As far as I know for VTEC to engage need to fulfill 3 inputs:
1) RPM
2) Speed
3) Throttle position

Since u mentioned that the rpm can drop to idling rpm, I suppose u r driving a auto gear box?

Nope on manual... Tried to take video yesterday night but the problem is gone. It's like on and off... zzz
Bro, For manual, with your gear engaged at 5th gear, it shouldnt be able to drop to idling rpm even if VTEC cant engage. It is as if your gearbox isnt engaged. Forget about my advise on ECU, u may need to check your gearbox.
If at 5th gear and rpm drops to idling rpm does it mean that the speed drops to 20km/h even when the accelerator is maintained floored?

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Post by Emperorcivic » Mon Nov 28, 2011 5:26 pm

if rpm drop to idling, means ur speed drops too?
if not, even if ur syncro mesh spoil, ur rpm still climbs bbut ur gear auto disengage.

ur problem damn unique.
but prolly could be due to tuning, or fuel pump or fuel filter?

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Post by Will_SG » Mon Nov 28, 2011 5:41 pm

All stumped by the symptoms! Very interesting problem ;p

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