blitz16v

This just started happening today.Drove to work all was normal and all was well, driving home yes car was warmed up all 3 bars, under FULL THROTTLE, the engine feels like its bogging and down on power, it hits vtec but its not running 100% I noticed if I put the pedal to the floor, and then come off it a little its catching up or something and accelerates faster like its running too rich? The car has 21k on it, and well maintained. I did the MAP sensor whack, all air lines look to be in place, what would cause all of this all of a sudden, I doubt its this sudden cold snap any ideas? It very weird when I put the pedal to the ground the engine just bogs, but if I feather it it will accelerate better wtf?
Could this be bad fuel?

S_Sense

Im new to the s2000 but in my experience with other cars, sounds like it could be water in fuel, dirty fuel injectors. easiest and cheapest quick fix (just to try, it might not work, like I said, new to S) buy fuel from another store ( I use the same BP at the top of my neighborhood. you might go to same store) Try a bottle of injector cleaner. I am assuming you are filling up with premium by the way. It could be worse, you might need a compression test or something. Good luck.

negcamber

See this thread:

https://www.s2ki.com/forums/index.php?showtopic=553872

Sound familiar? Ended up being bad gas.

blitz16v

Okay I just filled up with Chevron 93 Octane, and used the Techron concentrate to see if that was the issue. We recently had a deep cold snap and temperatures have been freezing lately. I will see if the fresh gas and injector cleaner, fixes it.

CKit

(BTW, some people with malfunctioning injectors did not get any benefit from injector cleaner)

blitz16v

Car has 21k on it, this car is treated religiously fluids, there is nothing wrong with this car, I have no idea why this shit started today

ChefJ

Has the temperature dropped extremely since the last time you drove the car?? The ECU may need to learn that the oxygen is more dense and it may be running lean or rich depending on fuel trim. Has it thrown any DTC's or is this thread based on what you are feeling??

blitz16v

Yes the temperature has dropped extremely as in much drier air. Tuesday morning our low was 40 and this morning it was 29, and the air is much drier denser, this morning it was fine when I drove it to work,when I left work around 5 in the evening it started doing this. That is very weird because my friend has an AP2 and his was doing this on the way home as well, is this a common occurence when there is a temperature swing thats fairly large?

eDiesel

I found that out the hard way.

blitz16v

On the drive to work this morning I played around and got a better idea of whats going on.

WOT from IDLE to 6K stumbles but after VTEC its full POWER from 6k on no hesitation.
Feathering the throttle[ about 85% pedal usage] I have full power everywhere, no stumbles no hesitation.
If my throttle cable is too tight or too loose, would this happen? What about the throttle position sensor?