08 misfires once in while
 

My 2008 has just started to miss fire once in a while (no check engine light yet). Mainly notice either when idling or when on thruway at 65 and car goes up slight hill but not enough for auto trans to downshift. If car downshifts and rpm goes up sounds fine. Its just when there is a little more load on the engine I feel it like stutter, feels like a misfire and some times at idle too.

Original spark plugs 71K miles on car. I have read through about the coil packs going bad. Its middle of WINTER here so way to cold for me to do anything, no garage to work in. Plus iam not sure exactly whats wrong, could be spark plug or coil pack or both?

then coil packs, I see whole set of 4 aftermarket ones for about 60 bucks were OEM ones are around that for each coil. So 4 times price difference. Are these after market ones any good? Oh do these coil packs come with a new rubber boot that goes over the sparkplug itself? Or is that a separate part?

For anyone who had similar problem can I get away with waiting for a few months till it warms up to replace plugs and ALL of the coils or iam I stuck taking it to dealer for them to check it out. No idea what the dealer would charge me to replace just the plugs plus what they would charge for a coil pack and would they just want to replace all of the coils or just one if they can even figure out which coil is going bad? Sounds like it could be a $600 dollar job I get hit with if I take it to a dealer(just guessing on cost).

First you need to borrow the scanner to locate missing cylinder (you have to navigate to so called mode $6). If it misses in one specific cylinder you may want to switch coils around.
If problem is the coil than you know what to do:)
other reason for car's engine to jerk could be the motor mounts transmitting vibration when cooling fan turns on, or even water in the fuel (if it contains ethanol it WILL contain water)

Have to buy a scanner
 

I have no idea were I could borrow a scanner so I guess I would need to buy one. The question is will the scanner reading info from the cars computer even know if and which cylinder is misfiring? Not sure how it could really tell for sure. Its not like there is an O2 sensor on each cylinders exhaust port. Not sure how else a computer could tell if a coil generates high voltage to the cylinders spark plug. I have no check engine light at this point, I would think if there is a code it would soon give me a check engine light but not so far.

I took a look at the coil packs today and didn't realize how easy they are to change. I might just take the gamble its the coil on one of the cylinders and replace all four, Rock Auto has OEM ones for $47 a piece. I called the dealer they wanted over $100 each, yikes what mark up.

Don't think engine mounts as it occurs with heater is not in defrost mode which is when the car kicks in the air conditioning compressor which turns the fan on. Its only 15F here so that's the only way the fan would even turn on at these temps. I also ad dry gas every other month during winter.

Thanks for the suggestions.

Like he said already try switching the connectors for your ignition coils to see which ones would be the issue. If you don't notice a change in power then that coil is dead. I didn't get a check engine light when my ignition coils went bad but I just decided what the hell and I changed all of them at once.

Don't go cheap on your ignition coils, I learned first hand when you buy cheap chinese crap. Mine only lasted 3 months and I had to get denso ignition coils.

Btw have you kept up with your routine maintenance on the car?

The misfire monitor measures time how long it takes to engine to rotate a 1/2 turn (for four cylinder engine. If cylinder is not firing the time will be longer compared to the rest.
The misfire monitor is not working under certain conditions but it counts misfires even if it does not trigger CEL. (However if all cylinders are equally weak, it will not count misfires either:)

ok
 

Ok I get it on how its figuring out a misfire. I would need to buy a scanner to see if it has seen any missfires which it must have as today it was miss firing while I was stopped at a light. At the light it did it 2 times were I felt it missfire but not always as at the next light it didn't miss at all.

After finding this thread https://www.fitfreak.net/forums/1st-...ion-issue.html my car is acting just like this guys car did. his were the coil packs. Since I planning on changing the spark plugs come this spring I think I will just buy 4 coils the good ones OEM from Rock Auto and hope it fixes the problem. I wont do the plugs until spring its just to darn cold now to do anything more that the coils. No garage to work in. Only 0F for high Sunday. Only one 10mm bolt a electrical clip connection and its out with a twist and pull. Since the dealer is asking over a $100 per coil I sure wont go there as it would be a $800 bill for a simple job if I had it done there plus reading through the thread I posted above checking the coils doesn't seem to work that well as they told him the coils were fine at first, my bet it doesn't simulate real world conditions.

I took a shot when I had my transmission problem not shifting into top gear which I have posted about here and I took a shot on that which fixed that problem.

Yes I do regular maintenance on the car and was going to replace the spark plugs this past summer even though there supposed to go 100K but never got around to it. but will this spring assuming the coil packs fix this problem. I don't want to get into changing the plugs unless I really have too. I would freeze my fingers off trying to in the cold.

I will post results after I replace coils. Have my fingers crossed. Yes I could buy a scanner then try swapping coils around and if it was summer I would but to dam cold here to mess around. Iam 90 percent sure after reading the thread above that I have same problem.

Have you ever done valve adjustments? I might be mistaken but at 100k you might want to take a look at your alternator belt to see if it's worn out or not.

No valve adjustment yet
 

I wont bother with that until 100K right now iam at 71K so not yet on valves. But iam sure that has nothing to do with this misfire. But will get to it at 100K. I did my old CRV I used to have valves at 90K and they only needed very minor adjustment. I also replaced the camshaft drive belt on my CRV as that was a rubber cogged belt unlike the one in the Fit that's a chain.

I plan on doing the fan belt this summer along with the spark plugs even though the belt still looks good. My only question about the fan belt is were can I get a good one like the OEM one. Maybe the dealer stocks OEM belts but not sure they even do. Many dealers I have found when it comes to belts and hoses get aftermarket stuff from local parts stores.

I got my belt from Amazon but make sure you get it honda oem because I read some belts might be too long or short.

The 100k maintenance I was talking about was only for your alternator belt. The valve adjustments should be done at 60k if I'm not mistaken from what other people recommend on here.

my relative's fit sport had been driven all over the US (Texas, New Jersey, now Califtornia, with 78 k miles; no valve adjustments, misfires or bad coil packs, however the steering wheel has vibration in D with vehicle stopped.
If engine has low torque cold (shifts at higher RPMs than used to do before, or stalling when put in gear after cold start, the valves may need adjustment but if it makes hiccup once in a while even at normal operating temperature I will suspect ignition components.
For coil removal:
The 10 mm bolt for holding the coil is installed into through hole so it may corrode and stick to the head, so locate an exit hole and spray penetrating oil in it when engine temperature is about 80...90 degrees F; the best temperature to remove a coil is about 70 degrees F. Use 6 point only socket for the job. Post the pictures of old coils.
PS if you will be local I would definitely hook up my scanner to check for misfires:)

Your relative's fit is well maintained then. I had to get my valves adjusted because it was stalled so much that I had to warm up the car for 10 minutes everytime.

I wish
 

I wish I was in CA to do this job. Iam Buffalo NY, going to be a high of 0F this Sunday. I wont have the new coils until Wednesday so planning on either Saturday 27th at 27F or maybe Sunday at supposed to be 49F a heat wave. Cant wait until its 70F as that wont happen until around mid May, OR did you mean ENGINE temp of 70F?. I will shoot some break free up whole from bottom. I will use Snap-On socket 6 point flank drive if you ever heard of that. Hopefully no problems removing bolt. Thanks for the warning. Funny thing my engine purrs smoothly until it misses once maybe every minute or two.

Yes bring the engine to this temperature (70F)

Ok
 

Ok I will getting parts Wednesday will do job Saturday the 21st. Supposed to be 27F, a heat wave then. Since the temp has dipped into the 10F to 0f the car has been running fine, go figure.

This should rule out valves, as they tend to cause problem with cold engine in cold weather.
The ignition system is sensitive to moisture in the air any dry condition (hot or cold with dry air) should help
it is a wild guess (I saw it on other cars but not on Fit) that under certain condition EGR valve stays slightly open when it suppose to be closed)

Coils are extremely easy to change, even in the cold (trust me, I know)! I believe the bolt is 10mm. The clips for the coils are "rocker style" so you have to press the clip on the end that is away from the connector (closest to the wire) to get the tab to lift up. Undoing clips is the one thing I hate the most with any mechanical job!

You might want to dab a little dielectric grease in the boot before you put the new coils in. Don't over tighten the bolts, they screw into a plastic part of the coil.

I have the new coils
 

I got the coils yesterday from Rock Auto. Hopefully weather is 32F this Saturday for the install. I spray the bolt whole from underneath with penetrating oil. Hopefully they just unscrew without a problem. I now have a check engine light on it came on Tuesday. I decided to order a Blue tooth scanner (http://www.ebay.com/itm/HONDA-BLUETOOTH-WIRELESS-OBDII-OBD2-ENGINE-FAULT-CODE-READER-SCANNER-DIAGNOSTIC-/251846317444?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2008%7CMake%3AHonda&hash=item3aa335d584&vxp=mtr) that with my smart phone I can use Torque light app to read what codes were set and then clear them after the coils installed. I need to find a list for what the codes are. My guess is it will be for one of the cylinder's misfiring. Hoping the coils fix the problem.

with 71k miles you are coming to the end of working life for spark plugs and coil paks; an occasional miss is the first warning and because its occasional misfire will be difficult to find on OBD inspection tool.
yeah, its expensive at $120 per cylinder but prepare for that necessary maintenance.
PS virtually all late model cars have coil plugs.

Rock Auto
 

I got 4 OEM coils at Rock Auto for a total of about 200 bucks. Even the dealer only wanted 100 each. Unless you meant spark plus too but there about 8 bucks each at Rock auto too. OEM ones not cheapo after market ones . I will do the plugs when it warms up sometime in May before any driving trips.

Doing job either this Saturday or Sunday waiting to see if its going to snow or not. Weatherman cant predict even the next day as I get different forecasts depending on were I look. One day its supposed to NOT snow and be close to 30F. Hoping I can get it done tomorrow. Only concern is that the 10mm bolt holding each coil doesn't snap off in the head. Will put a little anti seize when I reinstall bolt .

It will be interesting to know what code number is.