I'm gonna go on a limb here and say that perhaps in your case, the coasting causes the fuel injectors to fire to keep the engine from stalling. That is what I've heard. I try to compression brake but I do have to blip the gas. In the city, I nearly always drive in 4th gear with my foot ever so slightly resting on the gas. I wonder which is greater, the amount of gas spent blipping the accelerator or the gas expended by the injectors when coasting in neutral (P.S. not interested in a legal debate I know that coasting is illegal most places).

I do end up having to blip my accelerator quite a bit in the city because of all the shifting. I'm trying to clutch in every time I brake but there are certain situations where I just gotta rev match. I'd rather spend a little more on gas than prematurely wear my clutch.

 

Coasting is good for gas mileage.

 

I hadn't heard that before. Does it matter that I hav an automatic?

 

So I just did a trip out of town with some highway driving and my last fuel up rated at 28.6 MPG. I dunno if it's the highway miles or the lack of engine breaking/rev matching.

 

Thought I'd chime in, in an attempt to be helpful. If you get stuck with no good solutions, you might check valve adjustment. A quick compression test would tell you if the problem might exist.
I take care of my wife's 08 sport with 90k. The city mileage has dropped from 32 to about 24mpg. It's been a slow decline over the past 6 months. I've done all the normal corrections. Valve adjust seems likely. I've read of some owners needing adjustments at 40k. Though unlikely, it's possible that yours are out. I wish I could say for sure what's causing hers to drop. She hasn't noticed and I haven't gotten around to checking yet. I've been waiting for the Florida heat and mosquitoes dissipate, which just happened.
Good luck with it. They are great cars if taken care of.
Clogged exhaust a possibility?
Great forum by the way, kudos to the moderators (and contributors).

 

I wonder if I should do the idle learn procedure. Since owning the car I've disconnected the battery (actually replaced the battery) multiple times to work on the car. Dunno if resetting the ECU did something to the mileage.

I do notice my car tends to stutter when taking off in first but I always attribute that to me being to light on the gas but maybe a valve adjustment would help with the stutter. The problem is that if I give it more gas, once I get going, I feel like I can only stay in second very briefly and need to shift to third right away since I'm already getting into the 4000 rpm range. I actually find it easier to take off when going up a steep hill. I can get the car to inch forwards and take of smoothly and don't have the same problem with either a jerky start or a stutter like I do on level ground.

 

Idle learn procedure is pretty easy, so give it a try.

Otherwise, two things to check would be battery and coil packs. Not sure from your description, but our fit was stuttering at stoplights. It's an automatic so a bit different. It would sometimes stutter while highway cruising. We took it into a Honda dealer. They said 'no code, so we can't do anything'. From my reading, their next suggestion would be a valve adjustment. We narrowed it down to two possibilities - bad battery or coil packs.
Battery was at 4 years and was on it's way out. We replaced it with no change in symptoms. Next was coil packs. It's pretty easy to pull them to check - unplug connector, 10mm wrench, then pull packs from spark plugs, pull boots and look for signs of arcing or voltage trails. Fit's have a known problem with coil packs. Ours went out at 60k, though I've heard of them going at 45k (miles). We had 2 showing signs of arcing. I cleaned, added insulating grease and re-installed. This worked for about 4 months and problem came back. Wife was talking about a new car!!!, so I ordered 4 new ones from online honda dealer for about $60 (US$) each. No problems since. I've heard vw owners have similar problem, and dip theirs in epoxy as a cure.

So check the battery if you have any suspicions about it. You'll want to load test it vs simple voltage check. Theory is that electronics are sensitive to low voltage. This is more evident at idle (at stoplights, with brakes on), as alternator isn't charging and it's on battery power. Also check your grounds. Our Fit has wimpy ground wires. Stuttering was intermittent, but if coil pack is dead, you can swap them around to check - they aren't specific to any particular cylinder.
That's about all I've got. I haven't had to work on the car much, so don't know all the ins and outs.
Best of luck.

 

Thanks for the suggestions. I doubt it's the battery, I changed it myself last winter and it's a bigger 51r battery. Maybe the coil packs or the valve adjustment. I'm only at 50k miles so valve adjustment seems really premature but I was gonna take a look next spring/summer when I have time off work.

If you have a link on how to do the idle learn procedure, I'd be interested. I'm not so sure it would help. I've searched fitfreak but found so much conflicting info. Some say hold at 3k rpms until the fan comes on, some say don't touch the gas pedal at all. Also, it's getting near freezing here in Montreal so I'd probably have to let it idle a long time before I got the fan to go on (without touching the throttle).

 

The ILP is easy.

You can start with a warm engine that has been driven around, the <3000 RPM run until the fans cut on> is just to assure that the engine is warmed up.

1. Disconnect battery to re-initialize the electronics. (have the radio code handy)

2. Run engine to warm it up fully. You COULD wait for the fans to cut on (that is the way to be SURE) but I have been OK with just an engine at operating temperature.

3. Let engine run for 5 minutes without touching anything. (Actually, you could busy yourself by re-entering the radio code and setting the clock and stations) If the fans engage, don't count that as part of the 5 minute time period.


That is all there is to it.

NOTE that the car will re-learn the idle by itself, but if the procedure isn't followed, it could learn WRONG resulting in poor MPG.

 

You can also use a OBDII scanner to erase the learned parameter. Just plug in and scan, even if there is no codes and there is a erase feature it will erase the Random Access Memory. I have done it recently and it does work and did it on my dads old 97 Toyota. Just don't do it that often and don't do it before going for emission inspection.

 

Thanks guys! The only weird thing is that I've frequently disconnected the battery (negative terminal only) and I've never had to reset the radio stations. Why is that? Am I not disconnecting the battery long enough? Or do I need to disconnect the positive terminal? I'll wait until my next fuel up then I'll do the idle lear to see if I get any improvement.

P.S. I disconnected my - battery terminal for at least 20 minutes when I changed my headlights and I didn't have to reprogram my radio stations

 

Sounds like you're revving the hell out of the thing hitting 4k rpm in 2nd gear! I'm getting slightly under 40mpg in city driving. I'd check the sparkplugs /engine air filter, 20mpg would be ok for a 2 ton vehicle, but the Fit is only slightly over 1 ton!

Sparkplug condition check sheet is here: http://www.aa1car.com/library/reading_spark_plugs.jpg

But you'll need to check the sparkplug gap also, spec's should be in the spec's section of the owner's manual.

Air filter is a brilliant white color when new and gets progressively grubbier with age.

 

You also are measuring fuel economy with a different gallon.

 

Because: Newer radios are better. They "remember" the stations even when backup power is removed.

So, you are ahead of the game in that regard.



PS, Removing the negative terminal of the battery is all that is required, but if you remove the positive terminal also, you can check/add distilled water. (the cap near that side is often blocked by the big main fuse on Fits)

A low battery electrolyte level will shorten the life of the battery.

++++++++++++


Also, I wasn't aware that all scan tools would reset the memory. Codes, yes. Learn something new every day. I'll have to look for that feature...my OBD scanners are kinda old.

 

I'm using Fuelly to display in a mode called US, so it's most certainly using the imperial gallon. However, it was smart of you to assume I was using a metric gallon.

 

I'll try and check thanks for the heads up! I'm driving exclusively granny style and shifting before I hit 3000 rpm with no rev matching or down shifting, just breaking. Wow, high 30s is great!

 

Not you. The British dude claiming nearly 40 MPG city mileage.

 

I just started using fuelly and with only one fuel up I averaged 25.5 mpg
this is almost all city driving 98% with lots of sport mode and full throttle blasts

I can get 30-32mpg easy by changing my driving style but I like to rev this little puppy.

 

After my next fuel up, I will do the idle learn and if I build up enough courage, I'll check the plugs and coil packs. A previous poster shared a nice diagram for checking the plugs; how might I know that a coil pack is bad? Are there any tell tale signs? I know that the GD Fit is known to devellop problems related to the coil packs in time.

Also, when reinstalling the spark plugs, there is mention of "gapping". How do I properly adjust the gap of a spark plug? I don't want to modify anything, I want to remain on recommended factory specs.

It seems that all this spark plug and coil pack worrying is a bit premature, my car only has 50k miles which is about half of the expected lifetime of the plugs! My car does function well, I don't have ANY issues except getting a fuel efficiency between 20 and 25 MPG. I bet even my parents' Matrix R does better than that.

 

So I put on my new winter tires and rims today and with the front passenger side wheel off and the car in neutral, I noticed that when I tried to spin the rotor it would spin about half a turn before being slowed slightly by what I believe to be the brake pad. I did do a brake bleed job this summer and might have overfilled the master cylinder slightly. I find the max line is hard to interpret. So I removed a little brake fluid because I'm afraid that the piston would be forced to compress if there was pressure created in the master cylinder by the cap if it is overfilled.

Could this be the source of my woes? Just to be clear, the wheel turns easily and freely but when spinning it, it didn't keep rotating very long, just about one complete turn before it stopped.

Edit: come to think of it, although haven't yet changed the brake pads on my Fit, I just remembered that one pad isn't actually actuated by the piston so that must be the pad that is slightly slowing the wheel after about 1/2 to 3/4 turn. Maybe I should grease the inside of the caliper assy?