I've done some research and I just want to get some updated opinions before I start buying parts.


The car is a '07 standard, base model, Fit. Zero mods aside from seat covers. Just rolled over 80,000 miles.


I was driving around this weekend, parked the car, did my business, got back in and my problem started. The car was in neutral, idling, with the A/C on, and it started to buck a little. It wasn't constant, just once every few seconds the idle would drop and stumble. Then it would go back. I drove the car around the block in first gear, around 1,500 RPM and had no issues. When I parked again, the same issue happened.


The car also stumbled, felt like it had no power, and did the same sort of bucking when accelerating at low RPM. If I ran the car up to 3,500 RPM before shifting, I had no issues. But if I was shifting much lower, as I normally do around town, it would buck.


I drove home without the AC on and ran the RPM up higher than normal. I live in an area with some hills and low RPM going up hills was the worst bucking, but keeping the RPM up pretty much eliminated that issue.


From what I've read, I likely have a bad coil pack. Which one, I do not know. I was thinking it could be bad gas, fuel filter, or spark plugs. So I was going to do the plugs today since the fuel filter is a no go.


So my question is, what are the chances it is the plugs verses the coil pack? I will inspect the coil packs the best I can when I remove them to do the plugs. But I am not the most observant when it comes to hairline cracks and such, even when I'm looking.


As far as I know, the packs are original and I may be at the end of their life. Hitachi packs are $40 or $50 each on RockAuto. I can afford a whole set, so would it be best to do them all at once if I have to change one?


This topic seems to be covered fairly well. I'm mostly looking for opinions on the replacement schedule. Some say 80k miles is the lifespan and they are a maintenance item, some say replace them as the go bad, etc etc.


Thanks mates, you've yet to let me down.

 

On the way home yesterday, I rev'd the engine up a bit and got the flashing CEL. I believe that shows an engine misfire. I ordered a new set of hitachi coil packs yesterday and NGK iridium spark plugs.

 

Don't forget to do a valve adjustment, also!

 

I'll either have to take it to someone for that or look into it. I did the valves on an older D16 motor just recently. Price on a valve adjustment? $200?

 

Shop around, the price is all labor. 2 - 3 hours labor.

If you can find an independent Honda specialist near you, you are ahead of the game.

 

I have a trusted local mechanic. I am sure he can do it. He did my AC compressor and clutch on this car. I don't really enjoy working on my Fit due to time restraints. If I can't guarantee I can finish it in an afternoon (including weather), then I just don't try on this car. The coil packs and plugs will probably take me 20-30 minutes. Anyway, 2-3 hours is $120-180. I'm sure he will be on the bottom of that scale. He charged me ~$300 to do my clutch.

 

Yep coil packs and plugs easy half hour is to do.

Valve adjust is about 1/2 a saturday, if your a relatively experienced mechanic and not in a uber hurry.

 

More sounds like an ignition misfire . post picture of offending cylinder coil / plug

 

Yep, sounds about right. And I'd probably lump myself into 'experience DIY mechanic'. But this car is much newer technology than I've worked on. Half a Saturday doesn't sound too bad. I'll budget the time soon.

I will post photos when I get to it this weekend since my parts are coming from Rockauto and should be here Friday. It definitely feels like an ignition misfire to me.

 

It took me 1.5 hours to inspect valve clearances and adjust some of the valves.
high voltage leakage (arching from boot to spark plug well) will be more evident during high humidity, significant daily temperature changes.
if plus misses after extending operation at high temperatures, the internal high voltage insulation of the coil is failing.
on many late 80-s Toyota with coil inside of the distributor the number one causes of misfire was arching between the coil and distributor shaft reluctor teeth.

 

We did just get our first good rain storm here in Florida. The humidity is definitely off the charts. The issue started as the sun came out the day after a heavy rain, so it makes sense from what you are saying. It's rained pretty much every day since then too.


I am going to replace the coil pack tomorrow and probably inspect the valves in a week or two depending on free time.

 

On a 4x4 list I'm on we use the "Shade Tree Howler Monkey" scale,

http://www.4crawler.com/Banana.shtml

 

I didn't notice any physical defects at all. No cracks or springs that looked bad. Not even built up crud. No close ups on the plugs, but there seems to be two different brands. Also, none of them have markings on them. The hitachi replacements I bought had blue boots and said hitatchi on the top. I think the previous owner was running into the stock ones dying and replaced them one by one with possibly (?) cheap replacements. Not sure.


Plugs are in the same order they would appear when looking at the engine. Is the driver's side still cylinder 1? It was on older Hondas so I'm just going with that.





Only cylinder 4 looks less than ideal to me.





Anyway, it all looked alright but I replaced it with itatchi coils and NGK iridium plugs. Car runs fine now. So I'm assuming something was failing (possibly internal).

 

Any updates?
The plug on the left (which presumably came from cylinder closest to the transmission or #4) has most deposits so looks like coil for it was the one failing.
I bought new Hitachi coil just in case ( made in Japan, sold by Autozone) with blue tip and vent hole. The new version of OEM plug ending at -S01 has a vent as well. this will allow evaporation of the moisture from the spark plug well that could be drawn in with the air when engine cools.

 

Check PCV valve for a potential stuck open

 

I had a similar problem recently and it turned out to be a bad coil, once it was replaced I was all good.

 

This suggestion is irrelevant

 

Back to topic please

 

Back to the topic
Most forums are very hard on name calling and trolling.
Copy and paste "experts"are not welcome either
On cars with speed density induction system so PCV valve problems will not cause stumbling under load

 

Name calling and cursing out other forum members will not be tolerated here. Thread has been cleaned up. Consider this a warning.