I have a stock 2007 GD3 A/T with about 97,000 miles on it. I was having the stuttering issue and, in lieu of a standalone scan tool, bought a bluetooth OBD2 interface and a program (Torque) for my Android phone to help with diagnosis. I wound up having my valve clearances adjusted at a local dealership, which didn't fix the problem, and replacing my ignition coils, which did fix the stuttering problem. However, along the way I discovered another problem.

The software has a really cool feature which will automatically calculate your 0-60 time. When you are at a complete stop it will display "ready," it starts the clock when you start moving, and stops the clock when you hit 60 mph. The best I am able to do is about 13.1 seconds, both in D and S. I haven't tried using the paddle shifters, but it seems like it should be getting at least in the ballpark of the advertised 8.9s 0-60 time on its own.

Here is a recent timeline of things I've tried/changed:
1. Cleaned the EGR ports (this was an attempt to fix the stutter, prior to discovering the slowness issue)
2. Adjusted valve clearances (still trying to eliminate possible stutter issues, had this done at a dealership)
3. Discovered slowness issue (may have been there all along)
4. Replaced all 4 coils - fixed stutter, still slow
5. Replaced air filter and spark plugs (That's when I discovered the spark plugs, which weren't very old, were only FINGER TIGHTENED! Apparently the tech at the dealership had either removed or loosened them while doing the valves, and didn't bother to torque them! Drove around like that for two weeks) - still slow
6. (Not done yet) Try 93 octane, ethanol-free gas and go through the ECM reset/Idle Learn procedure. I normally use 87 octane with "up to 10%" ethanol.

That's all that I can think of that I've tried lately. After doing some reading, it seems that if the car is running rich then it may cause symptoms like mine. I also notice a slight gas smell when sitting at idle sometimes. I've captured some data for diagnosis, but that's where I need help.

Here is a link to the data:
Google Docs Spreadsheet

A few notes about the data:
- This was just a real short trip to test the logging, and doesn't include a 0-60 run.
- The Torque app "discovered" the O2 Voltage as a custom PID, so I'm not sure if this is the correct voltage or even the correct O2 sensor (doesn't the Fit have two of them?)
- The fuel trim values seem very high to me, but I have no real frame of reference
- Please let me know if there are some other items I should try to log, although there are a lot of standard items that show up with no data available, such as Air/Fuel Mixture. Also, Torque allows custom PIDs to be entered but Honda apparently doesn't give this information out for free.

Thanks in advance for any help or suggestions.

 

I tried filling up with some ethanol-free, 93 octane gas and doing the idle learn procedure. 0-60 time got worse, went from 13.1s to 14.7s.

I'll have to upload more data later, but fuel trims are still steadily negative. I think it is running rich during WOT, but don't know if the data confirms this or how to check it. I still need help if anyone has any advice. Thanks in advance.

 

You are comparing the a/t to the m/t. They are night and day as far as 0-60 times

 

also, upping the octane will not do anything. Not unless you have forced induction

 

Thanks. I looked a little harder for 0-60 times for an automatic and found numbers in the 10.9s - 11.4s range. My best (without trying manual paddle shifting) is around 12.5s, so I guess it isn't quite as bad as I thought. I'm not a racer or anything -- I am just using this as a benchmark to determine whether something else is wrong.

I am still a little concerned about my fuel trims and the possibility that my car is running rich. I notice the smell of gas while idling sometimes, but haven't determined whether it's coming from under the hood or from the exhaust. I'm also going a little crazy with my OBD2 scanner and trying to determine what the numbers mean, whether they are accurately mapped to my car (some of the PIDs are listed as "custom" or "alternate"), and whether they really indicate a problem. My only "problem" may be information overload and excessive, needless worry

I'd still love to hear some advice from anyone with suggestions on what OBD2 parameters are most useful to log for troubleshooting. It would also be great to know if there are any other Torque users out there and what custom PIDs you've discovered.

 

Yeah, I have a GE8 (2009 Sport) Fit, and I recently started using Torque.

I tried the Torque Scan plugin to try to find custom PIDs...and it returned hundreds of them, but ALL with the same return value (exactly the same), which seems like a bug. Unsure.

Anyway, what I *really* want to get out of Torque is tire pressure. Does anyone know the PIDs to get tire pressure (TPMS) values from the ECU?

If you want me to check my trim levels for you for comparison, I'd be more than happy to.

 

I've been using The "torque" app for quite a while on my supercharged '07 MT. Never bothered with the 0-60 or anything like that as I've been on the stock slipping clutch so I never launched the car. From what I've read the program is quite accurate as long as you are going off of GPS, should be within .5 + or -. Maybe you already know but there is a torque forum at the torque website with good help/info/discussions. Things I'd love to see are oil pressure/temperature as well as coolant temperature. I mainly use it to monitor short and long trim fuel ratio, IAT's, throttle butterfly values, as well as true speed/engine RPM's. The ecu is quite off on these readings when torque is calibrated properly and is referencing GPS. It is quite a handy tool and much more elegant to use than all other products on the market that I've seen. Very easy to use and customize to the data that each individual would want/need. Its funny because I've been meaning to to a sort of "review" of torque with photos of my setup as well as some screen shots of the data that I use. I've even got this program running on my 10" tablet with windshield mounted holder just to try for fun!
I find that with this tool along with my analog boost and analog AEM wideband I've got almost all the readings I need.

Also don't worry that your car is running rich. This car is very accurate on reading proper fuel ratios. I've got an AEM FIC installed and when tuning a little rich (anything over 14.7 open loop) the car throws a code very easily. You have to remember that the car goes into closed loop when wide open throttle and the ecu has been calibrated to have fuel as to not run lean in these conditions. The car is also in open loop when warming up FYI.

Hope this helps

 

You're over complicating the system. The TPMS read pressure and converts to voltage. When the voltage drops below the predetermined value you get the light on dash (or whatever). This is why when the battery's in the sensors start to die you get the light on as they are weak and can no longer hold the proper voltage reading. imagine if it was as you say, the manufacture would have incorporated it into the car. Even if it was something simple like cycling through the odometer screen fore each tire via the reset knob. What a great tool to have when at the track to keep track of your pressures for tuning purposes against laps/heat cycles!

 

Bad alignment can slow you down, check for gunk around your throttle body....

AND check the weight of the tires that are on the car vs. the stock ones. Any extra rotating mass added to the car will make it slower.

Also make sure all extra weight is out of the car... and if you weigh 300 lbs, that hurts acceleration, too.