Misfire (PO300 and PO302 codes), replaced plugs and coils already
 

Ahoy, Fit Freaks-
I've been watching the forum here for an answer to my current problem and have seen some related posts but nothing exactly like what I'm experiencing:

I've got a 2013 Fit with 150k on it (I know, bonkers. Travel for work) which has begun misfiring after a cold start, particularly in cold weather. I'll start the car, it'll idle fine, I'll head off down the road and lose power a quarter mile later with the CEL and traction control lights on, CEL flashing. Pulled the codes and found PO300 (random misfire) and PO302 (cylinder two misfire).

As per suggestions on the forum I replaced my plugs (all NGK OE), then the coil for cylinder two. Car ran well for a couple hundred miles, then misfired again. This time, I had misfire codes for cylinder 2 again as well as cylinder 1. Replaced the cylinder one coil pack, cleared codes again, and drove another couple hundred miles. Misfire again, now I've got codes for all cylinders having misfired.

My question is- what now? Is valve clearance the next likeliest culprit?
Sorry for the newb questions, any help would be appreciated!
-A

I'd be interested to hear the answer from the experienced mechanics on here. Interesting problem.

You don't mention which brand of coil you installed. Hitachi part# ending in 0053 works the best, others not so much.

BUT: By all means adjust the valve clearances. Should have been checked at 110K miles.

Post back with the results.

Valve adjust for sure, even if that doesn't solve anything it still needed to be done to rule it out as a possible cause, and for maintenance.

Acting up a quarter mile into a drive doesn't sound like a typical situation. I might want to see the freeze data along with the onboard snapshot data to see if anything else was affected besides misfire counters.

I'll just mention that when one coil starts to fail, usually the rest are on borrowed time.

When our '07 started to misfire at 123K miles, we replaced ALL the coils (about $200 from Rock Auto for the Hitachis) and haven't had an issue since.

That makes sense. If anything else was effected would it be showing a separate OBD code? All I've been getting is the individual cylinder misfire codes and the random misfire codes.

Trust me on this, lots of stuff can fail in ways that affect how the engine runs ---- without setting fault codes.

But you have legitimate fault codes that are setting for a legitimate reason, you just haven't found that reason yet.

The computer only knows it detected cylinder(s) that aren't contributing equally, but it has no way to determine WHY that is happening.








I started thinking of recalls, but the one I was thinking of for coils wasn't for that year car....but there are others that need taken care of if they haven't been completed yet:
Check your VIN for any needed recalls at
recalls.honda.com (USA)

Assuming you've got healthy coils, healthy plugs and a good recent valve adjust (These are MANDATORY SERVICE I don't care what Honda says... ) The next thing is try a bottle of Seafood or Techron injection cleaner in the fuel. You may have grungy injectors. I ran a can of seafoam per tank of gas about 3 times when I first got mine and it really got the thing running well. The PO ran cheapest gas she could find and didn't maintain things well...

HaHa "Seafood" you mean Seafoam....or the fuel system cleaner of your choice.

(Another popular one is BG 44K)

:rotfl: Freeking spell checker got me again..

YEa I find any of the name brand gas additives Seafood, Tehran, Lucas will help clean up your injectors..

FWIW pretty much all the high performance cars (Porche/Ferrari/Etc) Recommend Techron at least 1 tank a month to keep the injectors clean..

My personal experience was that the spark plugs were loose. The coil packs were alright and still in use approx 40K miles later.

You never mentioned if plugs were loose when you checked. Do any of the coil packs smell like gasoline (means the spark plug not sealed / leaking).

My expertly installed / properly torqued plugs came loose again in cyl #2. Used blue locktite and all has been OK ever since.

Hi Spike, when you used the Blue Loctite on your plugs, did you coat the entire thread length or perhaps just the top half of the thread length?

What torque setting again did you have them set to before they backed out? Thanks.

I used the Permatex blue paste in a twist tube and I didn't use a ton on each plug. Can't remember if I treated the top or bottom of the threads. I didn't take out the cowling the second time to torque. I depended on the threadlocker and my "calibrated" left wrist.

I did it by the book first time but it failed: spark plugs are torqued to 13 lb-ft and coil pack retaining bolts are 7 lb-ft.

Okay, thanks for the numbers. My plugs are somewhere north of 20 FT/LB (I set my wrench at 20 and did not remove the plugs), so hopefully they'll stay put.

I'm wondering if the previous owner of my Fit may have had someone check for this. There're two small circular round cowl fasteners on the cowl, one at each end, and one was missing. Or maybe instead, the windshield has been replaced and that would involve cowl removal.

No one touched mine (1st owner) and the plugs came loose on their own around 26K miles

2015 LX, CVT, 26-06-2018 @ 117,000 km
 

Just seen check engine, traction and steering lights come on this morning. I've been monitoring a misfire issue since 76,000 km after I had the dealership replace the CVT fluid. That was the day I started having all sorts of problems. I just want to note that the car was thurally pressure washed when I got it back from them so this all might be related to water ingress somewhere. I also noticed the CVT fluid plug got knocked out of place so I had to squeeze in there and push it back in.

The day I got it back I started having starter issues. It would take me multiple attempts at turning the key for the car to start. It randomly just wouldn't start and I ended up sitting there for 45 minutes trying to get it to turn over once. It just clicked once per try. Turned out to be the starter itself or starter relay recessed inside it. I replaced it about 19,000 km ago and never had a starter issue since.

Last fall I noticed a misfire or slipping feeling, I panicked and thought it was the CVT but I noticed it was only present when the engine was cold (the blue light was on). That was at about 82,000 km. Since then the problems been more and more noticeable. But only when the car is cold. Once its warm, I dont notice anything wrong with it. No MPG issues, no vibrations or anything.

This spring I started getting check engine lights on, happened 3 times before now, all 3 times it went away by itself. I caught the code the second time: P0420 which is fuel system/catalytic converter related issue. I tried putting fuel injector cleaner in it to see if that helped, but it didn't get me anywhere, or at least it wasnt noticable. Every time the lights come on, it's when I first start the car, so it's cold and the car does its rough idle BS.

I have yet to check the spark plugs, and I've also heard the parts/computer that throttles the fuel/air mixture when it's cold might be dirty or damaged. The fuel injectors are also 6 inches above the starter so water might have caused that problem if the injectors are indeed the issue. Again my fuel economy is good and and I only have issues when the engine is cold (though it idling warm isn't as smooth as when I first bought it). I do a ridiculous amount of driving and only have owned it 2.5 years now but I dont think that itself can cause issues.

If anyone has a permanent fix for this yet, please please respond back. I know once the problem goes away, you tend not to think of this forum again. I am guilty of this, so I know first hand how easy it is to forget. Anyways, hope this helps someone diagnose there issues and that someone finally posts a solid fix.

P.S. I'm posting this on multiple threads so you might come across this again. Misfire, warning lights and starter threads so far.

Cc152 - What we say here "might" not apply to your vehicle since it is a 3rd Generation FIT and we are 2nd Generation owners. We don't have CVT, etc as an example. You might be better off posting there if you haven't already.

But that said, I would check the spark plugs first. Just see if they can be twisted out by hand using the socket. To get to the plugs, you'll have to remove each coil pack. If you see that a particular coil pack is sooty / discolored / has the odor of gasoline on it - BINGO! you'll find that the spark plug is loose and needs tightened.

Don't over-tighten a spark plug. You can easily strip the threads in the aluminum head and to fix it'll take $$$$$$$$

I've successfully used a dab of blue threadlocker paste on all four of my plugs ('11 Sport AT) after #2 & #3 came loose.

That might solve some if not all of your problems. Mine too has the VSA and that light came on too when the Check-Engine-Light came on due to the loose plugs. Not syaing that a coil pack "couldn't" be bad but I think 99.9% of the time it is a loose spark plug giving you "misfire" codes.

Given that you say MT's rule, curious why you'd sell your '07 Fit Sport MT? I have exact same car with 219,000 miles and it still drives pretty much like new. Still uses only one quart of Mobil 1 every 6500 miles and still averages about 35mpg city and highway. No sign yet that original shock struts are wearing. I live in the WNY rust belt so have gone through more than my share of brake pads, brake shoes, rotors and drums but other than that, no major expenses. Front sway bar links had the boots rot out so had to replace those a few years back. DIY was cheap. Fun car to drive to boot. Even the wife likes it.