Engine bogging at low speeds
12-01-2003, 07:02 PM
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Engine bogging at low speeds
Ok, this has happened twice now. It's only been a problem in 1st gear and happens at about 8mph. If I slow down too much, then when I hit the gas, the car jerks back and forth hard and has no power. Now, I realize that it's touchy at low speeds in 1st, but this is definitely more than "touchy".
The only changes I've made recently are: changed fluids (oil, MTF, Diff.) and took some slack out of the throttle cable. I've checked the oil and it's fine.
What's the deal???
The only changes I've made recently are: changed fluids (oil, MTF, Diff.) and took some slack out of the throttle cable. I've checked the oil and it's fine.
What's the deal???
12-02-2003, 01:39 AM
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While I'm constantly trying to pinpoint the exact cause, I'm almost sure that it's the MAP sensor. Careful removal of the sensor and tapping it with the backside (handle) of a screwdriver should help. This may or may not be a permanent solution though.
You'll get a lot of different answers in regards to the problem but I know that it's not...
1. Your driving. I've experienced bogging a few times where revving the engine up to 3500rpms and slipping the clutch to the point where it may be burning and it still kept bogging. The car is obviously not doing something right causing the unsettling back 'n forth racket.
2. The ECU. This has been debated a lot but from several PM's I've got and first hand experience with a Mugen ECU that runs more ignition timing and a leaner fuel curve still experiences these bogs. If I'm not mistaken, the MAP sensor sends voltage to the ECU/ECM so the ECU only does what the MAP sensor "tells it to do".
If you do a search, you'll notice a lot of people attributing the cause to involve heat irregardless of each person's own theories. My current suspicion is that the MAP sensor part isn't very tolerant to heat (or the kind of heat found in an S2k) which is transmitted via the intake manifold. I can't say for certain whether it's the fault of the part, or that the S2000 generates higher amounts of heat, etc.
You'll get a lot of different answers in regards to the problem but I know that it's not...
1. Your driving. I've experienced bogging a few times where revving the engine up to 3500rpms and slipping the clutch to the point where it may be burning and it still kept bogging. The car is obviously not doing something right causing the unsettling back 'n forth racket.
2. The ECU. This has been debated a lot but from several PM's I've got and first hand experience with a Mugen ECU that runs more ignition timing and a leaner fuel curve still experiences these bogs. If I'm not mistaken, the MAP sensor sends voltage to the ECU/ECM so the ECU only does what the MAP sensor "tells it to do".
If you do a search, you'll notice a lot of people attributing the cause to involve heat irregardless of each person's own theories. My current suspicion is that the MAP sensor part isn't very tolerant to heat (or the kind of heat found in an S2k) which is transmitted via the intake manifold. I can't say for certain whether it's the fault of the part, or that the S2000 generates higher amounts of heat, etc.
12-02-2003, 05:41 AM
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Thanks, I'll keep that in mind. I'd be a little surprised if it was heat bog as neither occurrance was in heavy traffic or on very hot days, but since I don't have an answer, that sounds as good as any.
12-02-2003, 07:26 AM
#6
This situation can occur near freezing temps as well, as I have "made" my car do this at will.
I'm not saying that there isn't an "issue" nor am I saying that this is "normal" in the automotive sense, but it does seem like a common characteristic of many manual tranny, fuel injected, ECU controlled cars, especially this one.
Yes, it may have something to do with the MAP. Yes, it may have something to do with the absence of free play in the throttle cable that you just tightened up. I've always believed it to be a delicate combination of how the ECU, based on the sensor readings that it gets (from more than just the MAP), interprets what it is you are trying to make the car do. Usually, this combination involves low engine speed in 1st gear (sometimes in 2nd), sudden heavy throttle input, no use of clutch to get going. It's almost like the engine is given way too much A/F for its ability to use it.
You can avoid this situation all together by "clutching" to get moving faster, rather than employing excessive throttle. Once this "surging" begins, it is almost always necessary to clutch in/gas off and try again. Or, you can just go with the clutch routine as soon as you detect the circumstance when this occurs and with time, you will be able to recognise it before it happens. Again, I'm not saying that this is something that we should simply accept (and not complain to Honda) but more that many of us have conceded to.
I'm not saying that there isn't an "issue" nor am I saying that this is "normal" in the automotive sense, but it does seem like a common characteristic of many manual tranny, fuel injected, ECU controlled cars, especially this one.
Yes, it may have something to do with the MAP. Yes, it may have something to do with the absence of free play in the throttle cable that you just tightened up. I've always believed it to be a delicate combination of how the ECU, based on the sensor readings that it gets (from more than just the MAP), interprets what it is you are trying to make the car do. Usually, this combination involves low engine speed in 1st gear (sometimes in 2nd), sudden heavy throttle input, no use of clutch to get going. It's almost like the engine is given way too much A/F for its ability to use it.
You can avoid this situation all together by "clutching" to get moving faster, rather than employing excessive throttle. Once this "surging" begins, it is almost always necessary to clutch in/gas off and try again. Or, you can just go with the clutch routine as soon as you detect the circumstance when this occurs and with time, you will be able to recognise it before it happens. Again, I'm not saying that this is something that we should simply accept (and not complain to Honda) but more that many of us have conceded to.
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