vtec problems.

[iwantvtec]

ummm... after i had a dyno run, i realised that my vtec became very weird and "random" like sometimes it kicks in 4.9 rpm and sometimes it kicks in at 5.6, like its really weird yer any reason y's and how to resolve this problem?

[evoo]

im guess is something to do with the ecu... or the vaccum of how the vtec operaters... well thats my guess correct me if im wrong

[Limbo]

vtec works on oil pressure & rpm & temp. It has nothing to do with vacumn

Check that your still have the correct oil level first.
Make sure also that you have at least 1/4 temp reading.

Then if that's not it test the vtec solinoid. There is a a section in the DIY that shows you how to test it.

Last if that's not the problem get your oil pressure checked

[bennjamin]

it also depends on throttle load and position....IE you can accel. slowly to say 6000rpm then floor it it will "engage" like it just hit vtec

[iwantvtec]

really? coz i i realised when i did my dyno run i played round with my throttle body cord, to maximise my accelleration could that have caused it?? coz my oil levels r right.. n temp seems fine.

[bennjamin]

that might be it. the throttle cable maybe slipping or catching somewhere giving un even application to the throttle body + butterfly. Try and fix it u back to stock

[iwantvtec]

stock seeems shittty but. like it seems like its too "unsensitive", no force against the foot. Also how do i fix a sticky cable??

[bennjamin]

well its just a suggestion - what exactly did you do to it ?

FYI vtec will not kick in at 4.900rpm - it will kick in at exactly 5700rpm
other modifications may "resemble" the vtec kick in feel or noise such as air intakes or mufflers etc

[iwantvtec]

oh.... its def my vtec, like i see my rpm's shooting sometimes at 4.9 which is weird. Which is weird. Oh wat i did was i jus took off less slack out of my throttle cable.