misfiring Honda Civic

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jeff - we just crossed posts - so I'm going to get up to speed on yours and mine my be irrelevant .
 
I may have missed something on this thread because my patience ran out reading the "WAR AND PEACE" length posts here. But, are you missing the forest for the trees? Your problem showed up right after you changed the plug wire and/or added FP.

Fuel filter change did nothing.

DID YOU FOLLOW UP AND CHECK THOSE WIRES - WITH A METER?? My newer Caravan started "mis-firing". I thought it was a tranny problem. OBD code reader showed nothing and no CEL.

Broke down and took it to the dealer and they put it on their "scope": "DRBIII tested, performed no fault diag. - has intermittent cylinder misfire on #3 due to excessive secondary resistance. Replaced defective wire."

Today's "wires" are somewhat fragile and can have internal damage! Check those new wires!
 
The car ran perfectly fine for 5 days after installing the new spark plug wires - of course checking them can't hurt, gotta add a multimeter to my collection.

I just checked out the exhaust manifold. If there's a crack, it's too small for me to see, feel, or hear. I removed the heat shield and looked at it from as many angles as I could. Felt it up for cracks, couldn't feel any. Then I ran the engine and moved my hands around it, feeling for leaks. Nothing. Not a definitive test, I certainly could have missed something, but that's what I found.

I looked at the various tubes and hoses running about, all of them looked to be intact and properly secured - nothing fallen off, no big cracks.

Last, I did disconnect the oxygen sensor. Drove it around a bit, no difference.

jeff
 
Well , regardless of anything else brian , that link you have has a link within the link on a pinched O2 sensor wire that fits jeffs much earlier experience with H2O AND CEL .

What I'm not getting here is how p0132 alone and its causes results in all of the symptoms and all the other codes esp low rpm vs 3500RPM + esp with load ie 5th @ 5000 .

Well there is theory and there is practise . Can you elaborate on how others have had this and experienced a miss in lower rpm and not at higher with more load vs other types of "poor running" ?
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Thats not meant to be a challenge or doubtful of your information I just can't see it w/o something else present - and I'm completely ignoring any thought of ECM compensation strategies .
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I should be able to try out the vacuum gauge after work tomorrow. The Haynes manual has a sequence of tests to do, I'll see if I can figure 'em out (never done this before).

jeff
 
Well , hey , you are getting there and eliminating or reducing the probabilities of many things - which is what its really all about .
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FWIW Three most common mistakes with a vacuum gauge are ;
1)"Wrong" hook up - 3-5 ways to do this .Most common first time mistake - hook up "above" TB not below .
2) Read/use the gauge incorrectly or follow up incorrectly . Usually related .Sometimes there are some real subtlies involved in differentiation .
3) Not using the gauge in situations where its helpful .( Not talking about here )

Those pictures were very helpful !

I'm gonna add a tap and die set to your shopping list .
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Use some seafoam to see for an exhaust leak in da manifold. Baby Oil works too. Pull the vacuum line off da egr and do a quick test. See if that does anything.
 
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But, are you missing the forest for the trees? Your problem showed up right after you changed the plug wire and/or added FP.




I understand your "remote viewing" frustration. It happened to me when JHRZ had a fuse blow on his right headlight circuit when he installed new bulbs. The entire thread was full of smart people, but NOT ONE listened to the simple advice to try the bulb on the other side to see if the new bulb was defective.

Old bulbs - fuses fine
Two new bulbs - one side blows the fuse.
Observation - that bulb draws too much current - while other new bulb does not.

Logical conclusion - the problem is the fault of the new bulb.

The entire thread danced all around it and NEVER offered the sensible diagnostic technique. I felt invisible.
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Multiple misfires point slam you in the face with a baseball bat type of "all inclusive" cause. Fuel system could be an issue ..but they're rarely "transient" problems. They tend to linger/degrade/decay ..and don't fix themselves. That leaves ignition as the source of the issue ..with a heavy leaning to the cap/rotor/coil wire. After that ..then you broaden your search.

Everything that I've seen here sounds like it would have a passive influence on performance/drivability ..and nothing as drastic as detectable multiple misfires.
 
Gary,
Could you elaborate as to why you think it's an ignition problem rather than a fuel supply/mixture problem? I'm just trying to learn here.

This combo of symptoms:
- No apparent misfiring during first 2-4 minutes of driving in the morning. Shorter duration of good running during the day after shorter down time. Could this have something to do with the rich running the car does at start up?
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- No/very little misfiring at very light throttle
- Significant misfiring at moderate to heavy throttle at rpms up to ~3,500
- No/very little misfiring above ~3,500 rpms - exception is under WOT there are occasional misses - not nearly as bad as at lower rpms.

I'm trying to think of a reason an ignition problem would vary in the manner the symptoms suggest.

I found a couple interesting writeups that seem to apply:
http://www.aa1car.com/random-misfire/
http://aa1car.com/library/2002/us30232.htm

I'll have time to try out the vacuum gauge after work. Hopefully I can do it correctly!
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Thanks again everyone for your time and help!
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jeff
 
The problem here is going to involve 1 or more of the following systems and or components . ( These are the most likely ) In no particular order they are ;

FUEL TANK SOCK .
FUEL INJECTION PRESSURE REGULATOR
FUEL INJECTORS
IGNITION SWITCH
IGNITION COMMAND MODULE
IGNITION IGNITER -if separate from last item .
IGNITION COIL/SHIELDING
IGNITION SPARK PLUG WIRES - this includes more than we are currently discussing here . Good to know : internal coil - no coil lead - if my two parts stores are correct and this is as built .
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IGNITION CAP
IGNITION ROTOR
IGNITION CAP HOSE CLAMP
GROUNDS*/WIRING/CONNECTIONS THAT EFFECT SENSORS ECM(s)? and IGNITION ,FUEL ,EMISSIONS SYSTEMS
EMISSION CONTROL SYSTEM/COMPONENTS
THROTTLE BODY -mechanical condition as well as "maintenance" issues
VACUUM CIRCUITS/OTHER VACUUM LEAKS
EXHAUST SYSTEM -including possibly O2 SENSOR(S) wiring esp . AND EXHAUST MANIFOLD .
CHARGING SYSTEM/BATTERY(SOME ASPECTS OF STARTING SYSTEM )
SENSORS
HEADGASKET/OTHER COMPRESSION RELATED ISSUE .

The point here is to keep an open mind whatever you end up doing .So far we have eliminated the fuel filter and made less likely some other things .
Unfortunately we also have not so far , eliminated a single system .
( yes , I remember you have a functioning OBD2 system .)
Also this is not a judgement call or anything negative about what you have done so far - its just reality .

Now there are many ways to do this but since you now have the vacuum gauge we can talk about that .
The really cool thing here is in 20-30 min . of gauge work you are going to know A BUNCH that will help you neck down and hopefully eliminate the scarier PIA stuff .You will also be able to confirm/disprove much of your earlier work .
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Ok, I just got done with the vacuum gauge. That was kinda fun! I plugged it in where the brake booster line goes in. Seemed to work ok.

I started the engine up and watched the gauge. It settled pretty quickly at 20-21 - rapidly fluctuating between the two, almost like it was vibrating. The needle appeared darker at 21 - like it was spending more time there. But it was very fast. When the engine would shudder as it does occasionally, the gauge would show a 1/4 to 1/2 inch drop.

Next I blipped the throttle per the Haynes manual. The gauge would immediately drop to zero, then bounce back up to around 25. It would then go back down to 20-21 smoothly as the rpms dropped back to idle speed.

For s's and giggles I turned on the AC. This resulted in the gauge dropping down to 18-19, but with the same behavior. Same 1/2" drop accompanying the shudders.

The Haynes manual gives a bunch of suggestions for various behaviors. One goes like this "A slight fluctuation, say one inch up and down, may mean ignition problems. Check all the usual tune-up items and, if necessary, run the engine on an ignition analyzer."

The Mityvac booklet doesn't have any descriptions that match closely. The closest is for a burned or leaking valve - "At idle, burned or leaking valves will cause the pointer on the gauge to drop to a low reading and return to normal at a regular interval. The needle will drop from 1" to 7" at regular intervals whenever the defective valve attempts to close".

Thoughts?

jeff
 
Diagnostics is part science (experience and proper diagnostic tools to collect data) and part art (experience and a sixth sense).

As above keep an open mind - all too often it's something entirely off course that happened by coincidence. Other times it's tied to something you worked on.

A quick google of Honda Civic misfire = 44,000 hits. First page or two said coil/distributor/ignition system is problematic on these cars.

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I'm trying to think of a reason an ignition problem would vary in the manner the symptoms suggest.




Temperature/humidity (expansion,contraction) and gremlins can cause electronics to work/not work with and without a pattern.

I bet a shop would diagnose this problem in under 15 minutes. My money's with Gary - ignition system related.

Please keep us informed!
 
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Could you elaborate as to why you think it's an ignition problem rather than a fuel supply/mixture problem?




Well, I'm not saying it's the cause ...but given 2 of your 3 symptoms ..it would be the first stop on eliminating it as the cause.




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No/very little misfiring at very light throttle
- Significant misfiring at moderate to heavy throttle at rpms up to ~3,500




Identical symptoms would be present with bad ignition items. More load ..more cylinder pressure ..more prone to leakage if there is a weakness. Very common.

This one may or may not be present ..but you didn't really say if it was under "heavy" load ..and just mentioned at WOT which would make sense with ignition issues.

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No/very little misfiring above ~3,500 rpms - exception is under WOT there are occasional misses - not nearly as bad as at lower rpms.




Ignition components are sensitive to load. If there is any defect in them ..they show it first under load.

I tend to NOT lean toward fuel issues simply because you appear to be able to relieve the condition by lightening your pressure on the engine. Your fuel demand has to be the same at two given points at two different rpms. That is, lets say you're at 3500+ rpm with a light foot. No misfires? That's got to be the same fuel demand as another gear where you're using a heavier foot and get misfires. This makes me feel that fuel supply is not the issue here. It moves it MORE into "well, it could be" and moves ignition more into "most likely".

This doesn't mean that there isn't some fuel related issue going on here ...but I would find it one of the "unusual suspects" in the round up based on probable cause here.

Here's something cheap for you to try if you're willing. Get a spray pump bottle and fill it with water. Start your engine and spray down the wires and cap. Do this at night. If you see a lightning storm ..either wide spread or localized ..there's your issue. After liberally spraying the water ..and seeing no arcs ..drive and see if the condition shows itself. Not a conclusive test ..but one that I performed by accident once ..before I knew that my bought new 75 Chevy wasn't supposed to buck when it was cold (I'd owned chitboxed before that and they always bucked when cold).
 
Ok! THATS REALLY GOOD TO KNOW !
You may not realize just how much you eliminated and narrowed things down !
OK , now you should have in the MV booklet/haynes some other things "test patterns" you could quickly run with the VG . Also look carefully at the diagnostic presentations and please do tell me directly that you have at least 8-12 VG DIAGNOSTIC PICTURE/OTHER presentations ie readings/patterns etc to try to match with ?
I'm going to wait here for 10 minutes or so for your response .One of the aa11 articules or alink with in it had a VG "reading" for cranking/starting - find it and do it if your other material doesn't cover something like it .
now if you are running out of time at least do this ; watch for a change in how the fluctuations occur as you raise the rpm . Then , do the same as you come down the rpm scale back to idle .
Also pick 4/5 different rpm (higher) stabilise your rpm and observe the gauge - again with a little more emphasis on the flucuation pattern . You may need a notebook and or an assistant .

FWIW , you have very much reduced the probabilities of headgasket , exhaust manifold/system stuff , vacuum leaks , and certain mechanical problems concerning the TB ,various emission control things etc - just to name a few I CAN REMEMBER .
Also , I know there has been a lot to consider here but I'm going to ask you directly again . Do you have any of the old ignition parts esp the 3 old wires that still worked .Also have you at least inspected and dry wiped your TB ?
And now is the time if you have not done so already to find out about the ignition switch recall ?
Are these wires some sort of HP type ? In the picture they appear quite a bit thcker than stock What "type" of wire are they ?
Now would also be a good time to isolate that distributer clamp per previous if not already done .

( Forgot to tell you earlier , hope I'm not too late - save the old fuel filter - for later maybe )
 
Gary,
Great post, thanks a bunch.
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I'm not afraid of anything
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so I just went out and tried your spray bottle trick. There wasn't exactly a lightning storm, but after watching closely I saw some tiny blue sparks. I first noticed one in a spot on my hose clamp - zooming in closer and shading the area from street lights with my hands revealed more. I ran my hands along the cap and wires, and wherever I touched more tiny sparks would appear. Very small and I couldn't feel them, but they were there. So something is going on there! What it is exactly I don't know
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I think back to g20ooh's suggestion to use some hose or something to the insulate the clamp from the distributor and cap. Maybe for some reason it's started to provide an inappropriate path for the juice, thus fouling up the works?

If that doesn't help, what's the next step? Try a new distributor cap?

Thanks!
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jeff
 
Just cross posted there. Lemme answer those questions quickly.

OK , now you should have in the MV booklet/haynes some other things "test patterns" you could quickly run with the VG . Also look carefully at the diagnostic presentations and please do tell me directly that you have at least 8-12 VG DIAGNOSTIC PICTURE/OTHER presentations ie readings/patterns etc to try to match with ?

The Haynes manual just has the steps I followed. The Mityvac booklet has a few more - a procedure for checking for exhaust restrictions, PCV system check, and spark delay valve check. Lemme know if I should go through those too.

I'm going to wait here for 10 minutes or so for your response .One of the aa11 articules or alink with in it had a VG "reading" for cranking/starting - find it and do it if your other material doesn't cover something like it .
now if you are running out of time at least do this ; watch for a change in how the fluctuations occur as you raise the rpm . Then , do the same as you come down the rpm scale back to idle .

I'll print those docs out at work tomorrow
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and run those additional tests after work.

Also pick 4/5 different rpm (higher) stabilise your rpm and observe the gauge - again with a little more emphasis on the flucuation pattern . You may need a notebook and or an assistant .
I can position the gauge where I can see it from the driver's seat, so this should be easy.


Also , I know there has been a lot to consider here but I'm going to ask you directly again . Do you have any of the old ignition parts esp the 3 old wires that still worked .Also have you at least inspected and dry wiped your TB ?
And now is the time if you have not done so already to find out about the ignition switch recall ?

Nope, don't have any of the old ignition parts. I had to turn in the old wires to get the money refunded (AAP was very nice about that BTW). I'll check that ignition switch recall tomorrow. Have not inspected the TB - what should I do/look for? I've cleaned the TB on other cars before, with the spray cans and whatnot.

Are these wires some sort of HP type ? In the picture they appear quite a bit thcker than stock What "type" of wire are they ?
These are standard NGK wires - go to ngk.com, put in 2000 Civic EX, and this is what they specify. Also came up as OEM replacements on the site I bought 'em from. They rate as "premium" in the NGK hierarchy - 3rd best out of 4 types. Quite reasonably priced, especially as compared to so-called "performance" wires.

Now would also be a good time to isolate that distributer clamp per previous if not already done .
see my post above - I'll do this tomorrow as well.

( Forgot to tell you earlier , hope I'm not too late - save the old fuel filter - for later maybe )
trash day is tomorrow - I've still got time to save it!

Thanks!

jeff
 
Darn you, Gary! Beat me to the punch on that spray bottle test. Excellent advice.

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I saw some tiny blue sparks. I first noticed one in a spot on my hose clamp......Maybe for some reason it's started to provide an inappropriate path for the juice, thus fouling up the works?




It ran well for months without clamp insulation. Maybe something "changed" when installing the new wires? Hairline crack in cap....or it moved a bit???

Maybe a heavy blanket over the hood area to really get it dark?

The show's not over yet. But I'm speculating that Gary and greenjp (the Sherlock Holmes twins) are close to solving this BITOG CSI (crime scene investigation).

Keep us tuned in.
 
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