I had our Honda Civic Si serviced yesterday for the hanging throttle issue that many 2006 Si owners have reported. For those readers unfamiliar with this problem, it's basically this: When making a transmission upshift, the engine's rpm doesn't immediately drop as would typically be the case with other manual-transmission cars. Rather, the 2.0-liter engine's rpm stays at the point where the driver depressed the clutch pedal and closed the throttle, and then slowly drops.
This can be annoying as it makes it harder to closely match the vehicle's engine speed to the wheel speed via the next gear when the clutch is engaged...
There's an under-warranty remedy that Honda dealers can perform; it involves a reprogramming of the car's ECU. Thankfully, I didn't have to do a whole lot of explaining to the service advisor at the Honda dealership. Apparently, the advisor had dealt with another Civic Si owner a few weeks earlier that had the same upgrade performed.
After picking our Civic Si, I was looking forward to seeing how good of a fix the reprogramming was. And my initial response was: "no so good." Frankly, I had a hard time telling whether it was any different at all. But after a few more miles of driving, I started to notice a difference. At lower rprm shifts (around 3,500 rpm) throttle response is definitely better. But at higher rpm, there's still an annoying pause right after the start of the gear shift. The revs do seem to drop more quickly, but only after the pause.
I'll be curious to hear what other staff members (or other Civic Si owners) have to say about the reprogrammed throttle, especially those who haven't driven our Honda Civic Si in a while.
Brent Romans, Senior Automotive Editor
dragonzsoul says:
06:00 PM, 12/ 6/06
Yeah that sounds right. Honda claimed that the reflash wouldn't fix the throttle response issue, it would only help improve it. At least it helps with driving around in the city. When you hit those high RPMs, you're probably not in the city and probably not worrying about how smooth the ride is =)
spargo says:
09:52 AM, 12/ 7/06
from what i've heard this is to be expected unless you have a full intake/header/exaust setup. If you ask me, hearing that it seems like there is some backpressure in the system, and I remember them saying it had a uniquely designed intake to make the sound it does so perhaps thats it but i supose you cant be sure. If it is I'd really like to see honda at least come up with a HFP package that would fix this without ruining that beautiful sound.
-Spargo
vvk says:
10:07 AM, 12/ 7/06
When Euro4 emissions standard came out a few years ago there was a similar problem that affected manual transmission cars. Perhaps American Honda must consult their European colleagues to find out what the solution is.
kevin07si says:
11:33 AM, 12/ 7/06
I took my car to the dealer this morning and they claimed that there was no rev-hang problem and could not find any bulletins about it (this is probably because I have an '07 and the problem was "fixed" in '07). I even showed them a bulletin provided by dragonzsoul when he had his ECU reflashed but they didn't seem to understand that either.
Also, to follow up on the last post about the 3rd gear stickyness, I had them look at that too. And guess what...they couldn't find a problem there either. I explained that the problem is more obvious when the engine is cold, to which they replied that I could drop off the car at night and have them look at it in the morning. Oh ok! I really have time for that!
I think I'm going to buy some Amsoil Syncromesh manual trans. fluid and take it to an import garage in my area. I talked to a guy there and he said he would charge $30 labor for the work. I would do it myself, but I live in Chicago and don't exactly have the facilities (or expertise) to change trans. fluid myself.
I hope the info. helps some of you. I'll follow up if I end up having the trans. fluid swapped.
bennetpullen says:
11:46 AM, 12/ 7/06
Hmmm, I have this problem with my Fit as well, I wonder if I can get a reflash to make it better. Has anyone else with a Fit encountered this? I figured it was a drive-by-wire thing where there is a delay to you taking your foot off of the gas and the throtle actually closing.
hondacura4 says:
04:51 PM, 12/ 7/06
Ive heard of the Si related hang issue before from friends but I find it odd that some new TSX owners I know dont have the same issue. The TSX/Si have engines and transmissions from the same drivetrain family so......whats up Honda? Ive also heard that the more miles driven after the reflash the better the hang issue gets, but Im not sure on how true that is.
Another thing is that the DBW on the newer AP2 S2000s and all NSXs are virtually perfect. No rev hang or artificial feedback at all.
dragonzsoul says:
08:14 PM, 12/ 7/06
spargo:
honda does have a HFP exhaust for the Si. no perfomance gain though, just changes the tone of the exhaust =(
hondacura4:
the S2K and the NSX are perfect example of honda cars. everything else can be improved. i idolize those cars.
jerrywimer says:
05:32 AM, 12/ 8/06
That's really an odd thing for a 2006+ vehicle. My parents used to own a 1987 Ford Escort GL 4 door with a manual transmission (neatly sidestepping how many gears it had, since I believe but aren't sure that it was a five speed). It did something precisely fitting the description I'm reading for these Civics, in that the engine RPMs would hang between shifts. That was extremely annoying, and was a "new" feature to me, because the 84 / 85 model 4 and 5 speeds (respectively) that I'd driven prior to the 87 did *not* have the RPMs hang like that.
bromans says:
10:20 AM, 12/ 8/06
I neglected to mention in my post that the TSB's software update is only applicable to 2006 Honda Civic Si models within a specific range of VIN numbers. -- Brent Romans
spargo says:
11:04 PM, 12/ 8/06
so if the reflash doesn't fix the throttle hang what does it do?
I know about the HFP exauhst, to be honest I never found this annoying after all the hub-bub, but I wonder if somone using aftermarket parts would rid themselves of the "problem", from what I have heard it works, but I'd rather deal with something i don't even consider an issue than ruin that perfect throttle note.
-Spargo
civic_si says:
11:09 PM, 12/ 8/06
The rev hang is still horrible even with the reflash
http://members.shaw.ca/civic_si/two.avi
http://www.petitiononline.com/DBW
za07si says:
05:12 AM, 06/24/07
This is not a throttle issue. This is a direct side effect of being such demanding customers and Honda rising to the challenge. The reduction of weight in the inert objects in the engine such as the fly wheel free up wasted power, but causes this engine to be a slave to inertia. Once the engine revs up there isn’t any weight robbing it of power or slowing it down. Causing it to "hang" at the RPM range the throttle was released. The reason why you see this only on the SI is this is the only engine in the series using this flywheel. The closest relative the RSX type S used a weighted flywheel. Honda is continually refining this series to try and find the most reliable, fuel efficient, powerful engine out there, and I believe they will in time. If you do not pay attention to the rpm's and try to find a better "feel" for the clutch you can eliminate this by giving the engine a way to release energy.