Coil Packs
 

2004 Civic EX 66k. Car started to hesitate a couple weeks back (as the engine RPMs climb, the car starts to jerk a bit, almost like someone's stepping on the brake while I'm accelerating). CEL came on, and it was a misfire on cyl. 2. Changed the coil pack (for cyl 2) and all plugs. Three weeks later (after having no problems), car is starting to hesitate again. No CEL yet, but the hesitation feels just the same as it did the last time. Do coil packs sometimes go out together like that?

Re: Coil Packs
 

I haven't seen it from factory coils.
But they all were the same age, same miles. So it could be. Or a crappy A/M coil?
66k seems awful early. Most are well over 100k when I see them with a dead coil.

Every one I see is already completely dead, I have no idea if they go slowly or die suddenly. I see them on V6 the most.


When the CEL comes on and shows a misfire code, swap the parts to different cylinders, reset the light, make sure the code follows where the coil went. Say if it says miss on cyl 2, then move the plug to #1 and coil to #3. Run it and see where the code shows up next.

What did the plug look like that came out of the dead cylinder?

Re: Coil Packs
 

Thanks for the reply. The spark plug that came out of cylinder two did have a noticeable color difference. It seems slightly darker but I didn't notice any build up or anything (like oil or deposits). Best description is that it's "browner." I'll try your suggestion, but first I gotta get the car to throw a code. So far nothing has come up, but I know something is wrong.

UPDATE:

On my way home I left my reader attached to my car and a P0302 (Cyl. 2 misfire) occurred again. It's the only code showing up. Cyl. 2 has the new coil pack and all the cylinders have new plugs. Everything, including the plugs are OEM Honda replacement brand and type.

I was planning to do what you said (ezone) and swap coils and plugs to see if the misfire travels, but since she has a new coil and plug, I was thinking I should concentrate on the injector? And from there, if the problem persists, compression? It's odd though, because the car ran fine for a couple weeks after I changed the coil and plugs. What are the odds the new coil crapped out? Or maybe something is fouling the plug?

Re: Coil Packs
 

that is more likely.....i cant see a brand new coil going bad in a matter of weeks, no way, but you can swap it to try like ezone said,

i would start with a compression test, and pull the plug to see what its like, take a picture of it and post here

Re: Coil Packs
 

Sounds like a plan. I'll have my shop check the injector and do a compression test. I have been meaning to adjust my valves so maybe one of um finally went out? Idk, we'll see what the tests show and ill let you guys know.

Attached are pictures of two plugs pulled from my car. The plug on the bottom is from cyl 2.

Re: Coil Packs
 

I don't see any issue with those plugs.

Re: Coil Packs and so much more...
 

Update:

Just to refresh: we started off with a misfire in cyl. 2 with a brand new coil pack and new plugs. Mechanic switched the injectors in cylinder 2 and 4 and cleared the code. Test drove the car, and it developed misfires on ALL cylinders and had a random cyl. misfire code (5 codes total). Decided to move the new coil pack from cyl. 2 to cyl. 4 and cleared the codes. Test drove, car still hesitates but no codes are coming up anymore. At this point we're at a loss. Ideas? He suggested we test fuel pump pressure and clean the injectors, then go from there.

Re: Coil Packs
 

Hesitates, or misfires?
How and when?
Conditions?
I can't even think of questions to ask.

I would really need to drive it and experience the problem myself in order to go much further.

Re: Coil Packs
 

I'm fairly sure that the car is still misfiring even though the computer is not showing any codes after swapping the injector and coil from 2 to 4. When accelerating, usually in 2nd or 3rd gear, the car begins to jerk, as though someone were yanking on the e-brake or something. It's the same sensation as when cyl 2 began to misfire those weeks ago. Funny though, when accelerating in first gear, the car doesn't jerk or misfire as much as it does in the higher gears.

Re: Coil Packs
 

Got an EGR valve? Unplug the wiring from it.

Drive it around, see if the stumble/misfire feeling is gone.

Yes, the CEL will come on because it is unplugged. Keep driving until you know if that has any effect on what you felt.

Re: Coil Packs
 

I never thought of the EGR! Damn, you're good...haha. I've heard that if the passages get clogged it can cause misfires? Wouldn't it throw a code though (P0401)?

Re: Coil Packs
 

It's really tough to think of this stuff when I don't have the car in front of me to drive, feel, and get FF data from.

If I had known the misfire set while driving down the road, I would have got here sooner.

Yes it can cause misfires.
But not on the passages that are clogged.
The last OPEN passage(s) will be the one(s) misfiring.
Eventually, after the last passage clogged enough.


SO did unplugging the EGR make the miss go away?
Why haven't you been out driving it to find out?
LOL

Re: Coil Packs
 

I'd love to, but I don't have the car with me right now. It's at the shop and they're closed on weekends. As soon as Monday rolls around, I'll be down there checking it out with the mechanic. He's pretty open to my suggestions, and honestly the only reason I don't do these "easier" things myself is because I live in the city, so I'd need to do all these repairs/tests in street parking. I'll def. let you know once I get access to the car.

Re: Coil Packs
 

ezone, when unplugging the EGR, will I notice the change (if there is a change at all) immediately, or would I need to leave it unplugged for a few trips before I noticed any change?

Update:

Got the car back from the shop. They tested the mechanical aspects of the car (compression, valves, etc.) all check out good. I did a self test of the ignition system (tested the coil packs with a multimeter and after that the ignition system with a spark tester), everything checks out good and within tolerances. SO, that leaves me with the Fuel system, which I had been suspecting, an intake problem, or the EGR.

BUT.... after swapping the injectors to check them and cleaning the (1 week old) spark plugs, the mechanic says the car now runs "fine". The car no longer jerks as I accelerate, but still, I KNOW the engine is running rough because I can hear it when I stand by the exhaust pipe and I can feel it when the engine is at idol. It's also not logging any codes at the moment, even after I pulled the plug on the EGR and drove it around the block. Didn't notice any change and no codes got spit out as a result.

I'm thinking that it's still an injector problem, and that the only reason the car is running "okay" right now is because he cleaned the plugs. Once the plugs start to foul again she'll start missing again. I give it a few days before it starts jerking as I accelerate, but can a shitty injector foul a plug?

And to add insult to injury, on the way home, I stopped to fill gas and my fuel door won't open. I pushed the handle down and nothing happens. Great....haha!

idk..I'm just rambling at this point. I apologize...just frustrated as a novice diy-er

Re: Coil Packs
 

0.16 seconds, you know where.

http://www.fueldoorfix.com/
http://www.amazon.com/Dorman-924-275.../dp/B003P9US8W
http://www.instructables.com/id/Fix-...a-Civic-82170/


Unplug the EGR and drive it normally. It is immediately disabled.
It might take you a while to be certain of whether or not it made a noticeable difference though.
That's why I said "Keep driving until you know if that has any effect on what you felt."

Seriously doubt it is fuel.

Re: Coil Packs
 

Ahh, that sucks man. I found the fuel door issue and fix and installed it on mine about a year ago. It didn't break but I didn't want to take the chance.

Re: Coil Packs
 

I don't think the ECU will throw the code until several events occur (read: more than one misfire on the specific cylinder it is throwing the code for) so it might take several trips before the code comes. I think mine was taking 3 or 4 drive cycles.

I would drive the car until the code appears again, reset code, unplug EGR and attempt to replicate the misfire based on driving habits that initiated it in the first place. i.e. drive the same route to work and only drive that route, etc.

Re: Coil Packs
 

Stand by to link your thread here soon... LOL

Re: Coil Packs
 

lol, I know dude. As I was reading thru the thread I was getting all giddy at the possibility of dumping that beast on him ;)

Did you catch the 66k miles? If it is EGR passages, seems crazy to have problems this early. Stand by with your link to top tier gas, I suppose?

Re: Coil Packs
 

I tested injector feed circuits with a node light today, and all seemed fine, solid rhythmic flashing. Wasn't able to test fuel pressure because the kit I rented from our local parts store had some messed up adapter that just wouldn't cooperate. Didn't want to force the issue and break something, so I'll save it for another day.

In light of your dialogue between each other, I went ahead and read fsckewe's thread. I have not ruled out the EGR (and its associated ports/parts), so that's next on the agenda. I've been hesitant regarding the EGR since 1) to inspect and clean involves removing most of the intake system, 2) I am by no means an experienced and knowledgeable mechanical expert, 3) I don't own much automotive tools and am doing this in an exposed and public environment.

These aren't excuses, I'm just treading lightly in this process to minimize possible f**k-ups. I have been driving the car with no issues yet. No codes showing up and no hesitation upon acceleration. I'll keep working on the fuel pressure test while I await the vehicle to start hesitating again, at which point, I'll do as you said, ezone, and unplug the EGR to see if anything changes.

Re: Coil Packs
 

I did. One car might have the issue come up frequently, while another identical car might not have a problem for a long, long time.
Seems to have everything to do with fuel quality and driving habits.

But OP must either prove or disprove that EGR is the cause of the problem first, then he can chase down that road if necessary. If not, then there should be no need to.






BTW is this complaint a hesitation, or a misfire? To me, there is a big difference between the two terms. As long as everything is acting perfect, you probably aren't going to find a damn thing wrong.

Re: Coil Packs
 

when this entire thing initially began, it threw misfire codes for only cyl. 2. I knew something was wrong (before I even checked the codes) because as I would accelerate the car would hesitate. The best way I can describe the sensation: it felt as though I were feathering the accelerator but in actuality I maintained steady pressure. The vehicle would surge/jerk as the revs climbed. The odd thing is, it would only act up in the higher gears (usually second, third, fourth. In first, I didn't experience the surging sensation.

we replaced the plugs and changed the coil pack for cyl. 2. Ran fine for a week, then the sensation returned and codes showed misfire for cyl. 2 again.

Brought car back in, swapped injectors 2 & 4 and cleared codes. Misfire traveled to cyl. 4 but remained in cyl. 2 as well. Swapped coil packs 2 & 4, cleared codes, random cyl. misfire (300) and individual misfires for each cyl. showed up.

Cleaned plugs, tested for compression (good - tech said all were at 150), tested coil packs and ignition with multimeter and spark tester (good - all were around 49.0 to 50.0 kohms), cleared codes. And here we are, no sensation, no new codes, just playing the waiting game.

Re: Coil Packs
 

does it happen at a certain point on the throttle?

meaning, does the hesitation occur when the throttle is wide open, or half way open, or a quarter open? will the hesitation stop if you take your foot off the gas? or will it stop if you floor it?

next time it happens put the pedal to the floor, does it get better or worse when you do this?

Re: Coil Packs
 

The car hesitated from 1/4 throttle on. The problem seems load related. The more throttle I gave, the more pronounced the hesitation was, but the hesitation itself was noticeable from about 1/4 throttle and beyond. At idle and with my foot off the accelerator, I really don't notice anything, although I would say that the engine does run a tad bit rough at idle. I swear I can hear it missing every so often, esp. when I put my ear to the exhaust, but again: no codes, and no hesitation/symptoms so far. Still playing the waiting game.

Re: Coil Packs
 

do a compression test on all 4 cyls

Re: Coil Packs
 

Made me think:

Carbon tracking on the outside of the plug porcelain and inside the boot of the plug wire end can act like this.

Example:
http://ww2.justanswer.com/uploads/VL...n_tracking.jpg

If this is what has happened, all affected items MUST be replaced at the same time.
One will cause the other in a very short time if only one of the parts is replaced.


If this isn't what is going on, then ignore this post.

Re: Coil Packs
 

I wanted to give everyone an update on the thread.

It was a long and arduous battle with my '04 EX 5-speed. After weeks of intermittent misfires and days being spent in the shop running diagnostics that all came back normal, I had had enough (and so had my wallet, to be honest). I went to the dealer and traded her in for 2012 EX. I was pretty disappointed in myself, but I really don't have the time to be messing around with my car. I got a damn good trade in value, so I was game.

I returned to the dealer a couple weeks ago to pick up my new plates when I saw my old EX sitting in the service area WITH THE HEAD REMOVED. I didn't want to ask the technicians as they were busy, but that could be a hint as to what was causing the misfire. Valves? Head-gasket? Funny thing is the shop ran compression tests on the cylinders, and they came back within specs. I guess the shop I go to missed something, because that engine was in pieces.

Re: Coil Packs
 

A compression test alone doesn't always tell the whole story, and IMO many people don't know how to do it properly.

Maybe the dealer guys are on the wrong path too. The only way to know for sure is to see what truly fixes it.


You should have asked what was going on with it.