my step bro just got a '97 prelude with 162K on it. When he takes the rpms up to around 5k(about when the vtec is supposed to kick in correct?) he smells something wierd. Not necessarily a buring smell, i'm not sure what it is exaclty- i haven't gotten to look at it. But he also said that when the r's get this high he notices some black "carbon like" stuff coming out of the exaust.

Any ideas?

thanks!

 

I'd start with a compression check on the motor, see how healthy
it is.

 

Does it run past 6500rpm?

 

It sounds like vtec is still engaging correct? My car with 42k on it smells a little weird after I've done this aswell and when vtec engages there is a little black smoke that comes out the tailpipe, this is just excess fuel intended to keep the car from running lean and make it run longer. All of my friends cars do this as well, one with a 97 prelude and one with a 95 gsr. Pretty sure theres no big deal. My buddy with the prelude has 180k+ on his and still runs good.

 

Okay, and yes it does rev to 6500, he has had it pushing redline.

 

well that black carbon stuff is fuel.

h22's run very rich under vtec from the factory. look at any prelude with an h22, stock ecu and with or without aftermarket exhaust. the rear bumper will be covered in carbon