Partial throttle hesitation
05-16-2011, 05:11 PM
#1
Partial throttle hesitation
I'm having an issue with my 2007 S2000 that seems to be random, and not easily re-creatable. The car has 24,500 miles.
When getting on the throttle in the 2000-4000 RPM (partial throttle, full throttle doesn't seem to do it) sometimes that car will begin to accelerate, then hesitate for less than a second and then keep accelerating. The rpms still increase during this period, it feels like a momentary power loss. It feels very similar to when VSA kicks in to reduce power.
Its not the DBW, since the car clearly responds to the throttle input, then loses the power briefly, then gets it back again.
It's also not a heat soak issue either, as it sometimes happens at times that the engine is not heat soaked.
Loose Observations:
- Seems more prevalent when the temperature is cooler
- The car feels overall slightly slower when this happens, even after the hesitation
- The car seems to be slightly slower when VSA is switched off
I've tried the MAP whack, but i still have the issue. I am considering replacing the MAP sensor, but thought I'd post here. Also thought about the 02 sensor, but at under 25K miles, that would be surprising.
I am suspecting a correlation with VSA, Has anyone had issues with VSA, or something similar to this before? In search I found a user with an 07 describing the same issue, but the thread misdiagnosed the issue and BDW lag, and the owner sold the car for an AP1.
When getting on the throttle in the 2000-4000 RPM (partial throttle, full throttle doesn't seem to do it) sometimes that car will begin to accelerate, then hesitate for less than a second and then keep accelerating. The rpms still increase during this period, it feels like a momentary power loss. It feels very similar to when VSA kicks in to reduce power.
Its not the DBW, since the car clearly responds to the throttle input, then loses the power briefly, then gets it back again.
It's also not a heat soak issue either, as it sometimes happens at times that the engine is not heat soaked.
Loose Observations:
- Seems more prevalent when the temperature is cooler
- The car feels overall slightly slower when this happens, even after the hesitation
- The car seems to be slightly slower when VSA is switched off
I've tried the MAP whack, but i still have the issue. I am considering replacing the MAP sensor, but thought I'd post here. Also thought about the 02 sensor, but at under 25K miles, that would be surprising.
I am suspecting a correlation with VSA, Has anyone had issues with VSA, or something similar to this before? In search I found a user with an 07 describing the same issue, but the thread misdiagnosed the issue and BDW lag, and the owner sold the car for an AP1.
05-17-2011, 02:34 PM
#2
Registered User
I can definitely say it is DBW/VSA related. I've noticed this in my 06 before. Doesn't happen all the time, but it's there. From some research, it seems it's an issue with the A/F ratio/timing at the specific RPM. I don't know if Honda just made the car that lean or what. I know many 06+ owners have experienced this before, but I'm really not sure of the fix. Someone on the boards was actually able to tune most of it out with Flashpro.
Like I said, it's really hard to say. 06+ S2000s are so different from the others in so many little ways... DBW, fuel/timing, VSA, emissions, non-return fuel system, etc...
Like I said, it's really hard to say. 06+ S2000s are so different from the others in so many little ways... DBW, fuel/timing, VSA, emissions, non-return fuel system, etc...
05-17-2011, 02:46 PM
#3
I'd be pretty shocked if this is normal. I can't imagine any manufacturer would find it acceptable to ship a product with that kind of hesitation, let alone a sports car that attracts a more discerning buyer that is more in tune to the driving experience.
I'm pretty convinced something needs to be replaced or attended to.
I'm pretty convinced something needs to be replaced or attended to.
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