WTF- falling out of vtec...Y??

[AccLuDe12x2]

its not my motor but my gf's 00 civic ex has been going in and out of vtec above 5500, and now it wont hit vtec at all... and i have no clue what it is. the only mod on the car is an intake... so i can hear it crack vtec so driving her car until i get my H in isnt so boring, lol. but its not workin and i was hoping someone could point me in the right direction of how to fix this shit. its got 98,000, and it started falling in and out around 97 somethin

[g-wagon]

hows your oil level ? (not to sound stupid... but its a start)

[Stan2.2]

well there could be a couple of reasons....
1-Speed sensor is not work.
2-Ecu is faulty
3-vtec pins or wires not getting a good connection
4-faulty vtec sylinoid
5-and i have also heard of low oil pressure not allowing vtec to hit
6-some hondas of you try ti hit vtec before the car is warmed up will go into safe mod and not allow vtec to work right.

Thats all that i can think of but im sure im forgeting something

[AccLuDe12x2]

kk, im gonna check it out later and c what i come up with

[AccLuDe12x2]

ok so i checked the oil level and it was a smidge below the low hole so i'd say it needed some lol (ikno ikno i shoulda checked it b4 i posted but i've been workin on my H for days now and i didnt feel like popping the hood, plus i changed her oil like 3-4 weeks ago and didnt think it would get low so fast) so i took my dads black 04 tundra dbl cab iforce v8 (ive only been allowed to take her 2 other times on my own, i LOVE that truck) to walmart got some castrol brought it up to full took her for a whip and the vtec is back to perfect again -- now i know just cuz its a girls car dont mean it doesnt burn oil when u(I) beat on it haha thanks guys

[immeraufdemhund]

if you go to honda hookup and download any of the vtec service manuels (i grabbed one for the 5g lude h22a4) and at the end of i think the 10th chapter it talks about how to diagnose the vtec. I'd have to look to confirm the chapter. The files are kinda large but it's in pdf form and is easy reading.

yes the oil pressure is kidna critical to the vtec system from what i read. If you dont have good oil pressure there is nothing to engage the pin that locks the vtec lobe. I think it needs a minimum of 57psi (i coulda been misreading) so if you get less than that you have a problem.