[benjarrett]

Hey everyone,

Here is my issue. I have a 2001 5-speed. If I am driving below 60mph and I engage my clutch, my rpm's immediately dive down to zero and then pop back up to 1300 and then settle back to 900-1000. This happens in about a 3 second time frame. This happens well above the speed that auto-stop is supposed to happen, as if the engine wants to auto-stop. This becomes a problem when I am quickly downshifting and let out the clutch while the rpms are close to zero, I get a huge jerk as the clutch forces the engine back to life. This situation occurs every single day, almost on every shift I make. The only time this does not occur is when I am up-shifting with the engine under load, or when the AC is set to AUTO, such that auto-stop will not engage. The fact that this issue does not occur with the AC is in AUTO seems to indicate that is somehow related to the auto-stop function. I have read that other members have also experienced their rpm falling on a downshift, but I experience this all the time, regardless of speed.

The recent post "Engine Power Hiccup" could hold a possibility but I'm not having quite the same issue:
http://www.insightcentral.net/forum/vie ... php?t=4711

Any ideas?

Thanks

 

[kapps]

I have definitely noticed that when I'm slowing down, I'll push the clutch in around 1k rpm (when regen stops) and the revs will drop to zero then pop back up. I believe that's normal as others have posted similar info. I'm not sure if it should happen if your just cruising along and push in the clutch.

 

[masscommuter]

Right.
It's called manual shifting.
Put in the clutch, back off on accelerator: rpms drop to "idle".

The IMA control mechanisms can alter this basic fact of life,
but that's what's happening. When AC is on, RPMs stay up due to power draw.

To downshift without stressing this little gearbox, consider
- downshift only to neutral
- release clutch in neutral
- rev the engine to increase rpms
- now make your "rapid downshift" before rpms drop.
a.k.a. Double Clutching

 

[b1shmu63]

Masscomuter, I think what Benjarrett is describing falls outside the normal shifting behavior. Note that the RPM drops to zero, then pops up again to 1200, and settles back to 900. This sounds like an autostop or fuel system issue.

 

[kapps]

Yeah, it's definitely not a problem with shifting. The revs should drop to idle, but instead, the drop to zero. I'm sure it's a problem with the computer. Sometimes, it'll drop all the way to zero but other times, it only goes to 300-400 rpm and you feel it shake as it pops back up to idle rpm.

 

[b1shmu63]

At LOW speeds the point at which regen stops and auto stop starts is similar. This is normal. If it happens at higher speeds there is a problem.

At least one owner wishing to coast at high speeds with the engine off tried unsuccesfully to achieve this condition by modifying the vehicle speed sensor input to the computer.

 

[JoeMultihuller]

Hi BenJarrett,

Sorry to hear about your problem - indeed it does sound like a partially malfunctioning AutoStop circuit. Let's keep thinking about this:

Does your AutoStop work normally at speeds below 19mph?

At your higher speeds, does the AutoStop light illuminate at all when your rpms temporarily drop to zero?

What if you're going along at 55mph and shift into neutral as you let your foot off the gas pedal (clutch engaged) - will your engine stay off? If so, will it come back on when you then release the clutch pedal while coasting in neutral? If the engine stays off with the clutch engaged, does the AutoStop light come on or do the battery, oil, and brake idiot lights come on?

Hate to say it, but if I were to hazard a guess, I'd say that the problem is inside the ECM. Perhaps it's still covered by warranty since it's part of the fuel/emissions control system? If not, perhaps some head scratching by some of the smart people on this Forum might produce a no-cost workaround for your problem... (other than having you keep playing with the aircon control).

Relating to what Kip said, the conclusion I came to after trying to artificially induce AutoStop using the Vehicle Speed Sensor (VSS) signal is that not only must the speed be below 19mph but also the rate of change of the speed must be low; i.e., if you're in a panic stop then AutoStop will not engage as you're rapidly decelerating. I think this is the reason that simply disabling the VSS signal did not work in inducing AutoStop. Your ECM doesn't sound as though it's reading the VSS correctly.

Your description of the rpms is exactly what happens when I throw the clutch switch (i.e., return the clutch to normal operation) after temporarily stopping the engine by cutting off the injectors with one switch and simulating an engaged clutch with another switch. This is commonly but somewhat inaccurately referred to on this Forum as Forced Auto Stop (FAS).

Wish you well and if you can answer the above questions that might offer some more clues. JoeS.

 

[benjarrett]

Hi Joe,

Thanks for your questions. Here are the answers:

1) My autostop does work normally below 19mph.

2) At higher speeds, the autostop light never illuminates when my rpm's briefly drop to zero.

3) If I am traveling at 55mph and shift to neutral with the clutch engaged, in most cases the engine rpm's will drop to zero and then pop back up. No autostop or warning lights display. This usually occurs when coming off a freeway down a ramp etc. If I am accelerating, this issue does not occur between shifts.

4) My engine starts normally when either clutch or shifter are engaged from auto-stop.

I understand that most Insight's rpm's seem drop to zero around the 20-25mph range before auto-stop, but it just seems like mine does it 90% of the time, and well into the 55mph mark.

I understand what you are saying about VSS signal. I was just getting ready to install the clutch and brake and FAS switch after reading all the posts and observing it in other's Insights, but I wanted to address this issue first before I did that. Is Forced Auto Stop not the correct terminalogy?

Thanks!!!

 

[JoeMultihuller]

Hi Ben, thanks for your feedback.
Yes, FAS is the term we've adopted for Forced Auto Stop, irrespective of whether we're turning off the ignition key, killing the ignition, or shutting off the injectors. As was pointed out to us on numerous occasions, coasting with the engine off can be the largest single contributor to increasing mileage. (DUH :!: ). With my convenient FAS/Clutch switches, I find myself now doing it very often (http://www.KatieKat.net/Vehicles/Insight/FASClutchBrakeMIMA3.jpg).
I've also experienced the Insight's rpm drops at low speeds but haven't really paid much attention as to whether it occurred above or below 19mph, figuring the resulting jerk was part of AutoStop and my fault for not properly shifting or feathering the clutch. Over the next week or two whenever I drive the Insight (it gets babied and usually only used for longer trips) I'll pay particular attention to the conditions and symptoms you've described and will let you know of any revelations. Maybe others have some ideas...? JoeS.

 

[benjarrett]

I appreciate you monitoring your Insight to see if you have a similar condition. Sometimes I wonder if I am simply not driving mine correctly...

 

[JoeMultihuller]

Ben,
As I was driving the brand-new Insight (my wife presently is away with the other one) I tried paying attention to the issue you brought up. At speeds above 19mph it just acts normally when shifting - the rpm dropping but not going to zero. I simply haven't done enough slowing down or shifting below 19mph to definitively see exactly how AutoStop trying to kick in affects things. Will keep monitoring it and will post when I've put on more miles. Maybe some of our heavy-stop-and-go-traffic commuters can comment? JoeS.

 

[benjarrett]

Thanks for keeping on this Joe!

 

[02insight]

sorry to bring back an old thread.... but has anybody figured out what is causing this problem ?

 

[TRI]

On other Hondas they say to clean the throttle body inside with brake cleaner or the like as it may have a clogged idle passage. If it IS clogged the engine falls to zero rpm first until the ECU opens the throttle plate (has to), that's when you see the 'dancing' rpm.

Just a hint as I'm completely new to the Insight and could be wrong.

 

[02insight]

Video included

sorry to revive an old thead, didnt want to clutter up the forum with new duplicate threads.

But anyway, I am still occasionally having this problem where the Engine rpm drops to 0 before coming back to idle when downshifting and going to neutral.

Here is a video which shows it happening:
http://www.youtube.com/watch?v=OvAyiIXlIYY

Has anyone found a solution yet or know what could be causing this? I am guessing its probably just the way we drive. It could be taking into account if its in fuel cut mode, is it re-gening, did you press the clutch pedal all the way to engage the clutch switch or just pushed it down enough to downshift. Any wrong combination of the above 3 variables could cause this to happen.

I am worried that it may also be damaging to the engine, because when it goes down to 0, the engine sometimes makes a thud sound when it hits the 0 and starts back up.

 

[02insight]

I've noticed that this happens most frequently when decelerating in-gear from a speed higher than 25mph.

When decelerating in gear, when you reach 25mph and press the clutch, brake, and shift into neutral, the car will go into autostop.

But if you are above 25mph while decelerating in-gear, and press the clutch,brake and go into neutral, engine will go to 0rpm and jump back up. Probably thinking that all other conditions are good for autostop except the speed.

I have tried this and it happens pretty consistently in 5th and 4th gear when decelerating.