Hello folks.

First post here although I have been follow many great conversations here over thte last couple years. I owned a 1st gen for several years but had recently replaced it with a used 2013 2nd gen (bought it three months ago at 100,000km).

A couple weeks after purchase, i noticed a rough idle on a cold start (on a chilly spring morning). Got worried, read lots of threads here, tried to recreate/notice the rough idle and never managed to.
Yesterday, we noticed the CEL was on (no blinking) when starting up the car or soon after. Plugged in a OBDII and found something like 14 codes, varying repeats of the following: PO300, PO301, PO302, PO303, PO304.

I read some more threads, contacted a few car mecanics, and given they were not able to help me for a few weeks, one suggested I erase the codes, drive around, and see what happens when new codes appear. So I did.

We drove around 150kms since and have not had the CEL turn on since, I did not notice any unusual symptoms while driving or idling either.

I can say the spark plugs were changed by a mechanic a few weeks before I purchased the car. I did not know if all 4 spark plugs were changed or if they used the proper ones. The previous owner also had the Mass Air Flow sensor changed and all its wiring was checked but I have no further details.

What should I do with all of this? I am a mechanic noob, have little tools, but have some free time. I had already planned on getting the valves adjusted by a reliable mechanic this summer give the idling issue I experienced at first and because many here recommend it be done earlier than later. I'm also considering accessing the spark plugs and coils, to see if the previous mechanic did a good job, look for obvious damage, and if he used the proper spark plugs. A little worried I might make things worse as I have no small torque wrench.

If I was recommend to change the spark plugs for the proper NGK Iridium ones and replace the coil packs with new Hitachis, I would prefer to do it myself and obviously save several hundred dollars.

Please help my out with your suggestions!

 

Here's a quick and to the point video on valve adjustment, which also doubles as the video to do spark plugs changes. It isn't hard, just meticulous.

 

I would recommend torquing (or replacing, which, if yuh do, take a pic of em to show us) the plugs to 20ft.lbs., and making that particular task your responaibility vs a mechanic. i've known few who would torque plugs.
besides that, jump into general preventative works. you know, just basic stuff. you could, if you wanted, take pics of parts and post them here.
I for one would be cool with looking at them and giving an opinion.

In regards to your DTCs, I'll hafta look them up. in the interim maybe check out the battery terminals, get the corrosion off of em and in places where wiring grounds to the chassis.
just learned that our goofy electronic power steering system could wreck our idle! its got its own brain to tell the engine what rpm to idle at to make sure the alternator is putting out the juice it needs. Crazy stuff.

oh yeah, and valves as mentioned. at that mileage, for suuure. it'll make her happy.

 

Thanks Pyts and Red,

I've been looking around for an economical torque wrench for this low torque kinda work. Any suggestions? I had read its best to choose a torque wrench whose middle rating match with your torque need(a 10-150 ft/lb wrench for an 80ft/lb job, which is what i have for the wheel lugnuts). What kinda of wrench will I need for the spark plugs?

The codes:
PO300 = random misfire
After that, PO301-4 are misfires for cylinder 1-4 respectively.

As these misfires have not occured again since erasing the codes with the OBDII, should I be worrying about it? What is the recommended game plan?

Aside from Valve adjustment, the basic honda maintenance schedule, corrosion on the battery terminals, what other preventative works do you recommended Pyts?

Cheers!

 

It might be worth the few minutes to clean the butterfly valve intake with some carb and choke cleaner. I've seen a couple instances in non-Fits where due to age the leading edge would build up a fine layer of gunk and ever so slightly change the idle characteristics. It's probably 8 bucks for a can and a few minutes of disassembly to get at it.

 

integrating into the qoute made the reply to short so heres a bunch of words forming a sentence

 

Advance Auto and O'Reilly's will rent tools out, including torque wrenches. Unless you want one to keep, your call.

 

Hard to diagnose when it's running good. I'd get a coil and keep it in the car with the tools needed. When it acts up again, you'll be ready to pop in the new coil. To find the bad coil just find the cylinder that doesn't make it idle worse when you kill the spark. A bad coil can leave you stranded but you're usually just shut down for a little while.

 

Bengee, what brand and model OBDII code reader did you use ? Thanks

 

I have a Autel AutoLink AL319.

The misfire codes came up again, nearly 10 days after the first occurrence. I am currently trying a Gumout PEA treatment and have placed an appointment for a valve adjustment in about 10 days (could not get it sooner). They are going to check the spark plugs and I will ask if they can clean the TB butterfly valve while they are at it.

If the misfire problems persists, i think i will try changing the 4 coil packs myself. Hope its not the fuel injector....

Thoughts?

 

Maybe the plugs backed out again due to the threading . Thanks for the quick response . Keep us up to date . Best of luck .

 

you can find a new post on here about misfire due to loose spark plugs probably.. every week. that may be modest, honestly.
try not to worry in the interim, about other components being faulty and what not.

 

As promised, here is a little update after maintenance at the local honda dealership:

- I asked for a valve adjustement and they offered a package that included swapping the spark plugs for 404$CAD. I also asked them to clean the butterfly valve and they said that is not necessary and not usually done on Fits, but if I insisted, they could do it for 3/4hr of work. I accepted.

I tried to have them look at the spark plugs brand/model recently installed by the previous owner and determine their condition before swapping them (its like 30$CAD per plug at the dealership!). Well, they were not too cooperative and all I could get out of them was that yeah, they are not authentic Honda parts, they look like they are in decent shape and they are Denso . They recommended I change them because they were not Honda parts. They would not bother giving me the model number but they were willing to let me have the old parts after the work was done.

They said the coil pack on cylinder 1 looked a little suspect, it apparently had some rust on it. So they recommended I swap that too. 125$CAD or so!

So here are the parts that came out of my car:

Coil pack and removed spark plugs (installed by previous owner's car mechanic)



The removed spark plugs are Denso 3247 PKJ20CR-L11 Double Platinum Plugs, Gap: .043" (1.1mm)
https://www.sparkplugs.com/product.aspx?zpid=11118

I'm wondering how off or okay these plugs are compared to the OEM plugs?

On the first picture, you can see the removed coil pack from cylinder 1. Where is the rust theses guys were talking about (would that be the rust on one of those spark plugs?)?

My take is that the valve adjustement was a good maintenance call. I am happy I got the appropriate plugs in there now. I'm skeptical about the coil pack, I'm really not sure it needed to be replaced. Sounds like a quick buck for the Honda dealership?

Anyways, the car is running differently now. It feels a little more powerful and the idle seems smoother when i listen at the exhaust.

I'd love to hear your comments.

If misfires keep happening, I plan on changing the 4 coil packs myself this time around and save me a few hundred dollars. Keeping my fingers crossed that all will be well.

Thanks!

 

I changed out my coil and spark plugs and still had a rough idle. I changed out my throttle body cause that’s what a mechanic said was causing the problem. No one knew that a 2008 Honda Fit needed a valve adjustment. I showed them the YouTube, the Honda Fit book and Manuel and still said they didn’t know.
i YouTube valve adjustment and did it myself. Trust me super easy if you live in Los Angeles I’ll help you do it. You don’t need any crazy tools and I’ll help you do the idle relearn procedure. Do the Valve Adujustment.
most likely will be the exhaust valves that need adjustment.

 

Hi Jvas87, Thanks for your comment and the offer to show my valve adjusment. Unfortunately, I live on the other side of the continent. I'd love to learn how to do it myself but I know of no one locally that can show me. I don't dare learn without supervision, I don't figure I have enough car mechanic experience.

Regardless, I might not have been very clear but the dealership did do the valve adjustment on the last maintenance I just described. I will be chipping in some more here with an update on how it drives after a week or so.

Still wondering how good or bad of a match those spark plugs I found in my car are...

 

The DENSO 3247 is not an iridium plug, which the OEMs are. It is an option for these cars on rockauto, but it's pretty far from the OEM equipment. The OEM part is NGK 6774.

 

@bengee that coil is a mess. Good to replace before the heat damage leaves you in a problem. Cause was likely a loose spark plug.

 

if its listed as a suitable replacement then the car should be able to run on it. it looks to me like youve got blow-by on one of your plugs and that it discolored the coil

Also, whats up east coast! I'm in georgia now, newnan, so if you wanna talk cars, use tools, see how a healthy fit drives or help me bleed brakes
In seriousness though, aint the smartest drink of water, but I've got books n tools.. so if it suits yuh.
after making the drive from cali in a u-haul im happy to do anything fit related.

 

Awesome - hope the move went well.

More great quotes. Wrong but funny!

 

Great to hear you had them do a valve adjustment and get those incorrect plugs out. Platinum plugs alone have been known to cause these cars to run poorly. Platinum plugs have a different amount of resistance than iridiums and should not be used in a vehicle that was spec'd with iridium from the factory.

My highly trained plug gapping eyballs (joking) also tell me that those plugs may have too much gap. That will also cause these cars to run poorly. Also hard to tell in pics, but the crush rings don't look crushed. Overall looks to me like whoever did the plug change used incorrect plugs, didn't gap them, and didn't torque them properly.

Be prepared to keep an eye on your other coils. It's possible that they were damaged from improper resistance and sooting from not having the last set of plugs properly torqued.