forget vtec for a moment, but your car is lowering your red line to 6K this is some sort of limp mode or electrical error.

 

Are you sure the CEL isn't blown? It should come on when you power up the car but it's not running. You might be throwing a code but don't know it.

 

So the OP is saying that the car bounces off a 6k rpm rev limiter? Or it doesnt and you just realize that it does this when the car is cold??

Anyway, my AEM V2 with a dry filter was much quieter at VTEC engagement in the rain. Whether the filter was a little wet or not...I don't really know. Every time it rained, I wondered if VTEC engaged because I didn't hear it.

But the car made the same power...and I discovered that it was just quieter for whatever reason.

 

The OP clearly states that it's bouncing at a rev limit of 6K RPM when the issue happens.

If you put your foot down you can feel VTEC kick in with your butt. If you slowly work up to it you don't feel or hear it.

 

[QUOTE=triddle,Oct 21 2009, 08:30 AM] Are you sure the CEL isn't blown? It should come on when you power up the car but it's not running.

 

Thus it will never get to VTEC if there is something else causing the 6k rev limit (limp mode).

I think you are onto something with this thought.

Open Loop (Limp Mode) - ECU trusts nothing and resorts to a preprogrammed fuel map. The rev limit is lowered to 6k RPM.

Closed Loop - ECU uses all sensor inputs: O2, MAP, TP, Temp, etc. to adjust for "ideal" air/fuel mixture.

I would start trouble shooting anything that could cause the ECU to go into Open Loop mode.

 

Check your grounds I had this problem with a accord I used to have and one of the grounds was messed up so check them

 

Ever since I installed my CAI + exhaust and TP my S will not engage VTEC after I wash her or she has been parked in heavy rain. She will just bog as if i hit the rev limiter... First time she threw a CEL, and then disappeared within 5 minutes. Now no CEL is thrown.

I have to drive her around for 20 minutes after I wash her before VTEC will engage. In my situation I believe this is because water gets into the exhaust and either messes with the O2 Sensor or clogs the exhaust temporarily. There is always a nice pool of water hanging out inside my exhaust.
If I leave her on while I'm washing her or cover the exhaust tips with sammich bags I have no problems

My diagnosis is just a guess, I have no mechanical background...

 

My recomendation still stands. Buy a Helms or download one off-line and go through the VTEC diagnostic section IN THE RAIN. I still think it is a poor ground or a short issue that is showing itself due to the moisture change in the air which effects the conductivity of the short. Just my $ .02

 

no offense to anybody here.......just as a general tip.... please do read posts before posting......

pretty sure i'm more than capable to know a blown bulb or fuse if i'm capable enough to build a 400+whp motor and still have modest 10km/L fuel economy, and not to mention it sees 20+psi daily.......kekekek

back to the topic.....
once i get a hold of a real-time OBD2 datalogger, i will know more.

I AM leaning towards a wrong voltage reading coming out of the MAP or ECT, not 100% sure just yet.