Did all the right things. Waited for 600 miles before VTEC. When I first went over 6500 rpm I was thrilled. Now at 3100 miles, and sometimes going in VTEC just seems like a lot of noise, and no noticeable pickup. Other times it just kicks in and flies. Last night it seemed slow, it was a very humid night...could this be it? I live on Cape Cod, and the ocean air is sometimes at 100% humidity. Is the humidity going to affect the car that much, or should I be looking at ECU's and MAP sensors.....and can someone tell me wtf those things are and if they have memories and all. I read about it takes 40 runs to get the memory to normal again after it reads something "off". Thanks.

 

I think you're just seeing the environmental effects on the engine.

Heat (say over 80 degrees) will make the engine feel more sluggish. So will humdity. Letting the engine sit idling will soak the intake track and manifold, too, taking a minute or longer at speed to cool back down.

The MAP sensor delivers manifold pressure data to the ECU which it uses to calculate airflow. The MAP does not have a memory but the ECU does. It monitors all sorts of things to adjust the engine's air/fuel ratio and spark map to obtain optimum emissions output. It will also modify these based on any modifications you make to the car and how the affect emissions.

Again, it sounds like you're just seeing the results of a temp/humidity increase. If I'm right, the car will feel peppy when you first warm it up, but after it's been idling in traffic or at a stoplight it's a little down on power. This is common, it happens to all cars, but with our high compression ratio and radically tuned engine, it backs off of performance at high temperatures to avoid any engine damage.

 

Thanks for the info. The ECU is emmissions control unit? And MAP is manifold air pressure? Is there an easy way of checking these or need I go to a garage? Thanks again.

 

[QUOTE]Originally posted by woodyandy
[B]Thanks for the info.

 

[QUOTE]Originally posted by woodyandy
[B]Thanks for the info.

 

Interesting post today under different forum on valve adjustment robbing power. You may want to take a look.
https://www.s2ki.com/forums/showthread.php?...&threadid=27751

 

Don't know if you are famillar with this but, VTEC will not engage until the car is warmed up (2 or 3 bars on the temp gauge). Wouldn't want you to chase a non-exsisting problem around.

 

[QUOTE]Originally posted by johnyboy32
[B]Don't know if you are famillar with this but, VTEC will not engage until the car is warmed up (2 or 3 bars on the temp gauge).

 

Actually, the engine wont rev past 6*** RPM without it warmed up, so you know when you do that. And on my S2000 VTEC Does engage for about 500 RPM then it throws you into the seat belts when the limiter hits

I don't understand how people link low oil to no VTEC - sure the theory is there but if the oil is low enough to cause low oil pressure then your causing major engine damage and hopefully your light comes on. The VTEC hydraulics work off of the extra volume and pressure left over, low oil would cause something like "No VTEC during hard cornering" But you still have the main bearings to worry about. Low oil should be linked to "No Engine" rather than no VTEC

Back to the topic, humidity displaces Oxygen and therefor power available in your intake charge. Also the ECU has an aggressive set of countermeasures for climate changes, hot days will not just affect the density of the air, but the ECU seems to run the engine conservatively, better safe than sorry it seems.