I have 2008 automatic sport fit with 94000 miles, I've been having that dreaded ignition coil problem for the last year. I checked all 4 ignition coils and they all looked okay, no arcing or bent connections. I went through all 4 testing to see if it still stuttered when I put the new coil in each slot and it did. While closer inspection the I noticed that that red rubber around coil #2 & #3 looked dried and very dark compared to #1 & #4. I replaced the two #2 & #3 but I'm still getting the issue and now the check engine light turns on and off when it stutters during driving and I'm getting less power when hitting the gas after a light or stop. I'm thinking I should replace the other 2 coils but they are very expensive and I don't want to lay out the money if that not going to solve the issue. It happens even more so when i have the air turned on. not sure what else to do beside replace all 4. please help...

 

What is leading you to believe it's definitely a coil issue? Might not be if you're swapping around with no results. I'd imagine the car would be undrivable if two cylinders were down.

If you haven't already, Run a compression test, and check the plugs while you have them out.

 

When were the plugs changed last?

I suggest replacing all 4 coils and all 4 plugs. For coils, get either Denso or Hitachi. Denso or NGK iridiums for the plugs. All can be bought from rockauto.com or amazon for much less than a local auto parts store.

 

I also have to agree with datsun. Coil/plug is the most common problem, but it could be something else entirely.

 

Dried / discolored boots on the packs are a sign the plugs are loose. I'd at least torque down the plugs to spec. However, if you don't know the age of the plugs, or if they're some crap brand like Champion or Bosch, get rid of them and replace with the appropriate NGK or Denso plugs.

As a data point, when I bought my 2008 GD this summer (124xxx miles), it idled like crap, especially with the A/C on. When I replaced the Bosch plugs with NGKs, the idle completely cleaned up, and my in-town mileage jumped from the low 20s to about 27mpg. Near I as could tell, the coil packs were still the originals.

Off chance your valves are out of adjustment, too, but try the easy stuff first.

 

Fully agree with all of this! Ours seems to need the plugs re-torqued every 30k or so. Better to catch them before they eject and cause more severe damage.

 

If i buy two more and they are not the same brand as i bought from honda will that effect it? and how do I re torque the plugs? or just mean tighten the coil down?

 

OEM Honda is Denso or Hitachi, so no affect with those brands.

For the plugs, you will need a 3/8 drive ratchet, approx 6" extension (preferably locking) and a 5/8" spark plug socket. Torque to 13 ft/lb.

I just tighten by hand, but the torque rating gives you an idea of how tight they should be. I'd personally go higher than 13 ft/lbs, but that is the factory spec so proceed with caution.

For me, the work involved with getting to that point makes it worth swapping in a new set instead of just tightening the old ones, but you may feel otherwise.

 

Thats what i thought, had already tighten the old ones and no change, i will just have to replace the other two then. i should of just bought all 4 off of rock auto cause it a half the price then at honda parts store but I thought replacing the bad ones would fix it and i didn't want to wait, $100 mistake, live and learn. guess ill order the other two and see what happens, thanks

 

Agreed, i wouldn't recommend just tightening them without at least pulling them and taking a look at them for more clues. Plus, they are a relatively cheap maintenance item, might as well cross them off the list while you're in there.

 

Maybe I'm confused, but you seem to be talking about the plugs and coils as if they are the same thing.

 

I know they are two different parts, I just didn't pull the plugs out, only replaced the 2 coils.

 

OK, because we were talking about pulling the spark plugs out, checking or replacing them and re tightening them. I wouldn't invest in more coils till that's been done

 

Agree with datsun. If those plugs are original, there's a good chance they are fouled. If they were changed by a previous owner, they may not have used OEM type iridiums.

 

Car has always been mine. As long as I can remember they never been change so they are probably the orignals. Going to take them out and look to see what's up. If they were damage what should I be looking for? If they looked burnt?

 

94K miles and nine years is pushing it, even for iridiums. Lots of sites on the internet show how to interpret a spark plug, but my guess is that they'll look fine to the mark one eyeball, but the electrodes will have eroded a bit over time so that the spark is having to jump a bigger gap -- that can cause misfiring, even if the coil packs are perfect.

 

Rounded plug electrodes may affect the spark shape.
For less demanding driver 4 Hitachi coils (053) should be satisfactory.
After 45 minutes driving in 105 F degree heat,(a/c on) I checked the coil temperature coil #4 was 218 F, #3 was 200F #2 was 185 F and #1 was 170F. This explaining why #4 is typically first to fail. 220F will not melt a solder but can cause stress cracks in solder joints to propagate, causing intermittent failure. Should we rotate the coils every 30000 miles or so?
PS people on tight budget may consider full size domestic car made in late 70s as it can run on 6 cylinders out of 8 without much problem

 

I haven't seen any confirmation that the valves have been adjusted?

For goodness sake, DO IT. The Fit's valves (especially the exhausts) tighten up on a regular basis, and too-tight valves will cause the misfiring.


I check/adjust our Fit's valves every 60K miles and they have ALWAYS needed fine-tuning.

 

Not the Cadillac V8 - 6 - 4...

 

LOL, when brand new those ran on 8, 6, 4. Within about 30,000 miles they usually started running on 7, 5, 3 and then quit running altogether.