slalom44

I have a different opinion on this. I believe that heat soak starts the problem and the rest is caused by the momentum of your body being transferred to your foot. The same condition has been described as "kangarooing" and "bucking" when you're creeping along slowly in traffic (less than 2mph) then you press the gas pedal an your car starts bucking.

In an S2K, you are sitting very low to the ground. If you press the accelerator hard and heat soak temporarily bogs the engine, your whole body lurches forward and your foot actually presses the gas pedal further down. When the car finally surges forward, your body is thrown back in your seat and your foot is being pulled back. Then your body momentum swings back forward, so does your foot. You don't even know that you're doing it because you don't realize that your foot is moving on the gas pedal.

Don't believe me? When you think this condition might happen, try wedging your right foot against the carpet next to the gas pedal as you accelerate. By doing this, you don't transfer your body motion to your foot. This doesn't prevent the heat soak that causes it to bog in the first place, but it prevents you from going into the vicious bucking motion.

~blacks2k~

Happens to me every so often as well...always either in first or second gear at low speed...very annoying and embarrassing!!

Hero

it has nothing to do with heat soak. i've had it happen with only 2 bars warmed up in like 60 deg. weather.

it's just that kangaroo jump we all get. sometimes the car just acts up when you don't do everything right. it's more of a you problem then the car. don't worry, nothing's broken.

we've all done it...and we'll all do it again. best thing to do is just press in the clutch and start again. and yes, this happens to me from a very slow roll, not a stop.

im guessing this is why ap2 have the clutch delay as help to stop this? i don't know...makes sense i suppose.

Hero

check this too....everyone posting but one has an ap1

s2k aok

i get the kangaroo/bucking every once in a while, it starts easy but then amplifies as you are slammed forward and backward as your foot gets modulated by your body momentum and further modulates the pedal. with the 4.77s it is a lot more pronounced.

starchland

ok sure bang the map sensor...but has anyone ever tried cleaning the tiny little hole it gets its reading from?

JBrakeS2K

Same thing happens to me too sometimes. I've had the same thing happen when I'm driving the tanker trucks I work around at work, but the seat is springy as all hell in the trucks. I could blame it on this in the S2K aswell, but when I drive my eg it never happens. Neither of those have springy seats (obviously). I thought it was my clutch at first, then just operator error, but after reading the heat soak article my ideas changed. Its occured to me at all times, when the weather is cold, hot, and when ive driven the car for 5 minutes or for an hour. I have a stock chattery clutch in an 01 with 75k on the odometer. I would say its the heat soak issue, but thats just me. I learn to live with it, kinda funny looking like a tool sometimes anyways. Good times

sola77

The lighter AP1 flywheel 'may' be the biggest contributing factor as to why there are no AP2 drivers chiming in with similar experiences. On a 4 cylinder engine you can only get away with so light a flywheel on a street friendly car. 2 power strokes per crank revolution on a 4 banger, 3 on a 6, 4 on a 8, and 6 (yea) on a 12! Hence you can understand why a V12 requires the scantiest of flywheels and still remains supremely smooth. Crawling in 1st gear (guessing under 1500rpm) on my AP2 is not great but does not hobby horse either, slash a sizable chunk of flywheel weight off and I am sure it would be herky jerky. Try to keep your revs up just a bit and you should be able to avoid the bobbing.
Gary

slalom44

Nope. We all aren't going to do it again. As I said, I figured out what caused it and it hasn't happened again in years. If you want to live with it, that's your call. But it's so simple to prevent.

TreyDM

You guys are describing 2 different problems that ultimately have the same outcome.
Bucking and the feeling like a misfire under acceleration.

The "bucking" at low speeds is simply caused by a chain reaction resulting from slightly off fuel maps and throttle postion values (no oem ecu has perfect values). The first buck is usually caused by the ecu, then the combination of a very close first gear with the momentum of your foot create like a yo-yo effect that makes your foot press-backoff-press-backoff on the accelerator pedal. The first gear ratio is what makes it so sensitive.

Now the other concern. Under hard acceraltion, it feels like a misfire or "bog" when you are in your powerband. This concern is related the map sensor connector. Honda has a TSB in which the map sensor is replaced and a plastic lock is supplied with it to sercurely fasten the connector to the sensor. The actual problem is under extreme vibration, or engine load, (usually in vtec) the pins in the map sensor connector will vibrate so much they lose a good connection with the sensor. When the ecu sees no map sensor value it cuts spark. This usually happens so fast that the ecu doesn't throw a cel. This concern happens in any gear, usually third is the most common. To fix you really only have to buy the map sensor connector. Honda replaces the map also as a safety in case pins are damaged someone on the old map sensor from the vibration. Oh this concen also makes it self more prone to vehicles with exhausts systems. Honda knew how bad the problem was so they put those connectors on all AP2s from the factory. TSB applies to all AP1 vehicles.