only code i am currently throwing right now is knock sensor code on my b16. i'm throwing knock code because the sensor got broken, but people have been telling me that knock wouldn't be stopping me from having vtec engage properly. Just did fresh oem rebuild. new oil/water pump, t belt, ect. . . . also this motor was good before rebuild, vtec worked fine, also we cleaned out the vtec screen.

 

Check your speed sensor. if this isn't working properly the vtec WILL NOT kick at all until fixed.

 

check for any shorts from the vtec oil presure sensor cables

 

VTEC will not engage with a broken knock sensor. get it fixed.

 

i know that, and speedo works fine.

well if there was a short wouldn't i be throwing vtec code anyways. i think there are 2. pressure and spool.

hmmm, alot of people i know have gotten knock code before and still hit vtec. i was wondering, if i loaded a map onto hondata s300 and just disabled knock on there. would that alow me to hit vtec?

 

just borrow someones ECU that has the knock sensor disabled. I think thats the reason your not hitting vtec.

The factors that play into VTEC engagement:
RPMS
Oil Pressure
Knock Sensor
VTEC soleniod

Things that will STOP your VTEC:
VSS Sensor
Low Oil
Cold Engine

Taken from: The Official "Why VTEC doesn't Engage" Thread

https://honda-tech.com/forums/honda-prelude-4/official-%22why-vtec-doesnt-engage%22-thread-830163/

 

ok, so i used friend hondata, tried disabled knock, still no vtec.

 

ok tried a couple things , checked all wiring to vtec solenoid, power/ground. It was all fine. Now heres is what im thinking. The head was switched over from a b20/vtec setup to my b16, the reason because it had dual valve springs ect ect.. now, someone was telling me that when the head was setup for b20vtec or lsvtec they usually block some oil hole in the head. is that true? if so, i'm guessing i'm not getting oil pressure to the head, so then vtec is not wanting to work properly. my solution to this is prob getting a sandwich plate and run the oil line to head like lsvtec or b20vtec.