hello all. first time poster so please bear with me.

over the weekend i noticed that im having a problem with my 50,000mile 5 speed 2008 honda fit sport

at low rpm 1300-2000rpm and randomly, sometimes light throttle, sometimes moderate and sometimes full throttle, it jerks and stutters. always while trying to accelerate and very hard for me to consistently replicate.

i read about the coil packs and that they are known to go out around this time but am not sure if this is the same issue. most of the posts i read are people saying that it is jerking while trying to maintain a certain velocity and is easily replicated, not accelerating or another condition and at random intervals.

thanks for any help given and i hope that i am not judged on my post count or registration date.

 

You may need to clean your EGR

 

Check the Battery too. If the battery is going out it will cause a drop in voltage to the ecu and coils and injectors. Also check the alternator belt for slippage. Seafoam works good in cleaning the carbon deposits but be careful not to hydro-lock the motor. I would not add seafoam into the oil either but they say it wont hurt if instructions are followed. I just think its not needed and you dont want to wash away the moly and ZDDP coatings off the engine parts.

 

Most likely ignition coils. I had a customers Fit do that, no check engine light, just a stumble now and again, coils fixed it...

 

You are probably right but what cause them to go out? I know Heat is one reason but there is more to that. I found this Part 1 -Honda COP Coil Test (3.0L) .

 

Did it begin right after fueling up?

 

i didnt pay attention to where i was on the tank when it started, ive gone through 2 tanks since so that rules out bad gas but i see your line of thinking is probably more related to the fuel filter.. i will probably replace the filter this weekend (if it looks bad) just to rule it out

 

First, buy an OBD II tester (ca $50) and check for what your Fit tells you; most probable it is spark plugs and coil packs but when you test you'll have a good idea. Its the first thing that nubs should do.

 

its getting progressively worse. meaning its starting to climb up the rpm range. ill look in to a tester but i bit the bullet and bought a coil pack. ill let the forum know what i find out when it arrives.

 

Sorry, I should have mentioned many of the auto parts chains will perform an OBD II check for you at no cost. Thats especiaslly true if youre looking to replace one - or more - coil paks. Buying just one coil pak may not 'solve' the problem. Chect Discount Auto, OReilleys, Autozone etc and see what they'll do for you before you open the box of that coil pak.
good luck.

 

I would say clean the throttle body with sea-foam spray and load up the motor to clean the carbon. All the things I have been reading say its either EGR or carbon knock. My wife's car had the exact problem at 20000 miles and the car ran better with premium. I ended up trading it in on a Accord.

I would also say ethanol caused the problem at least with my wife's car. It still could be the coil or at least the boot but at last resort. I miss the days of spark plug wires.

 

Picked up a code reader. Plugged it in. no codes. No misfires detected. I cleared everything anyway and went for a quick drive. Misfired again and still no codes. After the coil shows up and doesn't fix it, ill try sea foam and clean the egr.

 

Did you buy just one coilpack? There are 4 of them, one on each plug.

Are you going to rotate the new one onto all the cylinders to see when the misfire goes away?

 

Avoid e3 spark plugs, they suck

 

Oh yeah, I completely forgot about plugs. Change them, sometimes they get replaced with cheap ones and it causes problems. Replace with whatever Honda calls for.

 

yes
plugs are good. that was the first thing i checked.

 

If you're due for an oil change, if you do it yourself, I suggest doing a crankcase flush with Gunk 5 Minute motor flush. Don't drive your car with the chemical in your oil! When you pour it into your crankcase and idle your engine, it will dissolve the buildup in the engine. My 08 Fit has close to 40k miles, and runs smoothly. I've been doing my own oil changes with the crankcase flush, and it helps the motor stay clean inside. It's a 5 speed too. If the flush reduces the problem, it could be the valves needing an adjustment.

 

With the plugs being controlled by the ECU will a chip for these actually improve preformance? Looking at going with ngk lazer plugs.

 

Oil is fresh and clean but thates not a bad idea. As far as the valves go, i would imagine these engines have hydraulic lifters but maybe someone thats gone through the head before can speak up.

 

Not hydraulic so adjusting the valves would be a good idea too. Look at the coils for burnt or discolored plastic.