imported_twizzlerboy

Hey everyone,
I've been doing a bunch of research about vtec wiring and I'm a little confused on what i need to do...

I had an all stock cx eg hatch and swapped in a complete z6. I also swapped the ecu with an si ecu. I thought the vtec would work without doing any extra wiring as I've been told that the eg cx is already wired for vtec. I am quite positive that I cannot feel it kicking in, but I don't get a CEL.

I can only find information about mini-me swapps and b-series swaps so I'm not sure what I need to follow.

Any advice would be appreciated.
Thanks!

imported_fiercecivic

unless ur running a dohc u wont FEEL vtec kicking in, u can probly hear it if you have an intake and exhaust otherwise you cant tell much on a stock z6

zeeman

iTrader: (1)

well was there plugs already on the engine harness for the vtec pressure switch or solenoid? If not, i can guarantee vtec isn't working and that you will need to wire it up.

CaptHowdy

or you have the wrong ecu, heh.

the car will complain that A. vtec doesn't work, and B. that the vtec pressure solenoid doesn't work either.

I think it's 21 & 22 error code if I remember correctly.

imported_twizzlerboy

I have a p28 ecu, it's not throwing any codes.
I do have an intake and exhaust and I don't hear any noise change anywhere between 4 and 5 grand.
I've driven a stock eg si before and you do feel it, subtly, but noticably enough so I know what I'm looking for.
The plugs are already there, the engine wiring came with that engine.
Any ideas?

RajunCajun

Check that there's no leaking coming from the vtec solenoid. You may just need to change the o-ring. That's what happened to me.

imported_SaYjAiBaO

hm i can't tell if my vtec is working either but the motor feels much better than my old d15b7. if it was leaking you could see it right? my vtec solenoid is as dry as a bone on the outside.

anyways, i reused my stock wiring harness on my 94 cx. only the 92 cx came prewired for vtec. what i did was get 2 new wires, connect it to the solenoid and pressure switch, and pin it directly to the ecu. it's a sohc so i can't feel if vtec is kicking in or not but it does pull nicer up top. if you do it like this, make sure you pin it to the right spots. get a diagram of mitchell or something. next thing i want to do is wire up the vtec into my shift light (VX cluster ). this way i know for sure when it exactly kicks in.

92extremehatch

unless the ecu is chipped vtec wont kick in until 5500rpm at least on a stock ecu

zeeman

iTrader: (1)

i've seen stock p28's with the vtec crossover set at 4800rpms too though. Vtec on SOHC is barely noticable. If you're not getting any CEL's and everythings wired up and plugged in, its probably working.

imported_twizzlerboy

The car I have is a 92 cx, maybe i'll just have to pull it apart and take a look at the wiringon the ecu and see what's there and what's not. Most sources say that vtec should kick in at 4600 or 4800 rpm, i've seen 4500... but either way i've taken it up to 7500 rpm (didn't think it should allow me to do that) but as far as i know the ecu isn't chipped.
If all else fails maybe someone could tell me which wire receives power when vtec kicks in and I'll just wire up a light to it and see if power is being sent to the solenoid.

RajunCajun

I believe the green wire running to the solenoid recieves power. I could be wrong. But I think black is ground and green is power or "signal".

imported_fiercecivic

rev limiter on those is 6800 rpm ur ecu must be chipped, ur ecu could have the vtec option removed thats why ur not hearing vtec and ur lights arnt flasking a code

imported_twizzlerboy

the p05 ecu has a 6800 rpm redline, I'm running a p28, it should be 7200

imported_95bluelx

yah mine kicks in just before 5000 it's an unchipped p28, to all those who say u can't notice vtec on a single cam , honestly....., obviously it's not severe as b series, but it's there and u know when it kicks in. It's strange that it's not throwing a code though, never seen that, maybe it is working and all these people are right sohc vtec just isn't noticeable (although, notice it on mine). Give Nick at teknotik a call he's good with ecu's, I hear Zeeman is good too, go see whoever's closer.