I have to say that if this were , say a 1980 buick...I would say you have a faulty coil! .... I don't know if this is true in the Hondas case ...but when some coil start to have problem, they only manifest themselves at certain RPM ranges...or when the coil hits a certain temperture
misfiring Honda Civic
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deepsquat ,
I agree - fully with your general observation AS DESCRIBED .
Could some kind of intermittent "coil problem" or some combination of primary side "low grade problems"(EX. BUILT WITH HIGH RESISTENCE IGNITION COMMAND MODULE , + now little higher resistence ignition switch ,3/4 grounds .....etc ie "stacked") that "present that way" be present here ? YEP - its one I keep wondering about - as a "second" or "third"
However ,
jeff has produced some really good roadtest data and reported it well .
Then there is the replacements , services , and changes made , and the MM work .
AND then there is the VACUUM GAUGE .
IF only certain things are considered here then many like that pop up .
THE ACID TEST is to fit all the data all the time - over time c..... so that won't cut it - unless I MISSED IT .
Most don't seem to realize what the VG COMBINED WITH HIS ROADTESTS allow and disallow - never mind all the rest .
IF we were all starting over again from jeff's first post and I could change ONE thing it would be to have had a FULL SET of VG readings FOR ALL his 1ST ROADTEST .
I agree - fully with your general observation AS DESCRIBED .
Could some kind of intermittent "coil problem" or some combination of primary side "low grade problems"(EX. BUILT WITH HIGH RESISTENCE IGNITION COMMAND MODULE , + now little higher resistence ignition switch ,3/4 grounds .....etc ie "stacked") that "present that way" be present here ? YEP - its one I keep wondering about - as a "second" or "third"
However ,
jeff has produced some really good roadtest data and reported it well .
Then there is the replacements , services , and changes made , and the MM work .
AND then there is the VACUUM GAUGE .
IF only certain things are considered here then many like that pop up .
THE ACID TEST is to fit all the data all the time - over time c..... so that won't cut it - unless I MISSED IT .
Most don't seem to realize what the VG COMBINED WITH HIS ROADTESTS allow and disallow - never mind all the rest .
IF we were all starting over again from jeff's first post and I could change ONE thing it would be to have had a FULL SET of VG readings FOR ALL his 1ST ROADTEST .
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Howdy folks. A few things to report, though I wasn't able to do much over the past several days, with family stuff and Easter and whatnot. Should be able to get back on the diagnosis wagon tomorrow
I checked and cleared the codes again on Saturday. Got the same set, with a small twist. Got 0300 through 0304 - random/multiple misfires as well as individual cylinder misfires. Got Honda code 1399, some sort of ignition or misfire code. Also got O2 sensor code 0135 - the 0132 code I'd gotten before was for high voltage, this one's for malfunction. The CEL came back on while I was cleaning the TB, so perhaps that caused it? Anyway, I cleared the codes and have driven the car a bit over 100 miles since. I've been careful to avoid the conditions that cause the misfiring, and the CEL has not come back on (yet).
My observation that the idle was improved is no longer true. It was during the particular trip when I initially reported that, but it later rides it was back to the occasional stumbling.
I've got checking/cleaning the IAC valve on my to-do list for tomorrow. I will also run it through the series of VG tests again. Any suggestions for other things? Is there a way to hook the thing up and drive around with it?
Failing any "eureka" moments, I'll probably end up driving it around for a while longer until the weather warms up (not gonna ride my motorcycle to work in 30 degree temps), then take it to my shop to see what they come up with. If it is a valve/timing issue, it's beyond my capabilities. But hopefully with the reams of "test data" I'll be able to supply them with they can quickly diagnose the problem.
jeff
I checked and cleared the codes again on Saturday. Got the same set, with a small twist. Got 0300 through 0304 - random/multiple misfires as well as individual cylinder misfires. Got Honda code 1399, some sort of ignition or misfire code. Also got O2 sensor code 0135 - the 0132 code I'd gotten before was for high voltage, this one's for malfunction. The CEL came back on while I was cleaning the TB, so perhaps that caused it? Anyway, I cleared the codes and have driven the car a bit over 100 miles since. I've been careful to avoid the conditions that cause the misfiring, and the CEL has not come back on (yet).
My observation that the idle was improved is no longer true. It was during the particular trip when I initially reported that, but it later rides it was back to the occasional stumbling.
I've got checking/cleaning the IAC valve on my to-do list for tomorrow. I will also run it through the series of VG tests again. Any suggestions for other things? Is there a way to hook the thing up and drive around with it?
Failing any "eureka" moments, I'll probably end up driving it around for a while longer until the weather warms up (not gonna ride my motorcycle to work in 30 degree temps), then take it to my shop to see what they come up with. If it is a valve/timing issue, it's beyond my capabilities. But hopefully with the reams of "test data" I'll be able to supply them with they can quickly diagnose the problem.
jeff
If its back at idle just do your gauge at rest . If you can set it up - do the cranking one out of AA11 - I have a more detailed list for that .
I think the shop is the way to go here - if nothing breaks loose before the weather - you have taken a pretty good run at it - I'm convinced one way or another you have more than 1-2 things going on .Then again you might catch it - and the FP/TECHRON ...ETC .
Its just amazing how fast you can go with the right scope etc esp. ignition and fuel .
If its a reasonable cost maybe they could straighten out your cap hardware while you are there .
I'd want to take a look at that 90k service receipt and make sure if the valve adjustment was done or not - just for my own understanding - it "might" have been "somewhat optional" .
What does the factory manual say on when to do after 90k ?Is it something like "listen" every 30k and do as needed ?
Anyway , cleaning sensors ,and running around doing any other good maintenance activity can't hurt and can only help .(Old lists/posts - still good for other troubleshooting/maintenance point of view) .
(You might want to make sure you have some dielectric grease and antiseize compound on your spark plugs) .
For the long haul if previously you used carburator cleaner on the TB AND scrubbed and rubbed a little hard then in the future be prepared to clean it more often - they originally had a nonstick coating that helps keep them clean .
If you had access to a tap and die set you could do what I call the "tokyo tune up" by cleaning up PT/chasis grounds .
Just about a year and a half a ago on another familly members Honda by cleaning up 16-17 grounds and replacing the ignition switch we were able to avoid replacing the SRS module ,ABS module ,Ignition coil/something or other? ,and a window regulator that was slow .
Two dealers and one independent shop all wanted to replace all the above when all it really needed were the grounds and a switch .These were reputable people and the independent was wondering and although everybody pulled out their diagnostic equipment they believed their gear and the "standard failure rates" on these items instead of thinking a little outside the box - ie what affects them all at the same time and is simple .19K later , I'm still feeling vindicated but it doesn't always go that way .
Whatever you and they do , put the VG on it when you get it back .
For on the road testing I usually use a secure tee fitting and run a secured (long) vacuum hose to the cabin( both ends clamped) .As far as routing to the cabin it depends - sometimes thru the cowl somehow - sometimes with the hood on second latch - and "roped" - some its better if left unspoken here .(You obviously don't want the hose pinched or falling off) .
I also use two people - its easy to pay too much attention to the gauge and not the road when things start happening .You really do want to write stuff down - short term/long term benefit .I'd do all this only after eliminating everything at idle - and if then still faced with only a "rolling miss" .
One thing I was curious about on your Sat am roadtest ; were you able to go thru 1/2 one time each w/o a miss of any kind ?
I think the shop is the way to go here - if nothing breaks loose before the weather - you have taken a pretty good run at it - I'm convinced one way or another you have more than 1-2 things going on .Then again you might catch it - and the FP/TECHRON ...ETC .
Its just amazing how fast you can go with the right scope etc esp. ignition and fuel .
If its a reasonable cost maybe they could straighten out your cap hardware while you are there .
I'd want to take a look at that 90k service receipt and make sure if the valve adjustment was done or not - just for my own understanding - it "might" have been "somewhat optional" .
What does the factory manual say on when to do after 90k ?Is it something like "listen" every 30k and do as needed ?
Anyway , cleaning sensors ,and running around doing any other good maintenance activity can't hurt and can only help .(Old lists/posts - still good for other troubleshooting/maintenance point of view) .
(You might want to make sure you have some dielectric grease and antiseize compound on your spark plugs) .
For the long haul if previously you used carburator cleaner on the TB AND scrubbed and rubbed a little hard then in the future be prepared to clean it more often - they originally had a nonstick coating that helps keep them clean .
If you had access to a tap and die set you could do what I call the "tokyo tune up" by cleaning up PT/chasis grounds .
Just about a year and a half a ago on another familly members Honda by cleaning up 16-17 grounds and replacing the ignition switch we were able to avoid replacing the SRS module ,ABS module ,Ignition coil/something or other? ,and a window regulator that was slow .
Two dealers and one independent shop all wanted to replace all the above when all it really needed were the grounds and a switch .These were reputable people and the independent was wondering and although everybody pulled out their diagnostic equipment they believed their gear and the "standard failure rates" on these items instead of thinking a little outside the box - ie what affects them all at the same time and is simple .19K later , I'm still feeling vindicated but it doesn't always go that way .
Whatever you and they do , put the VG on it when you get it back .
For on the road testing I usually use a secure tee fitting and run a secured (long) vacuum hose to the cabin( both ends clamped) .As far as routing to the cabin it depends - sometimes thru the cowl somehow - sometimes with the hood on second latch - and "roped" - some its better if left unspoken here .(You obviously don't want the hose pinched or falling off) .
I also use two people - its easy to pay too much attention to the gauge and not the road when things start happening .You really do want to write stuff down - short term/long term benefit .I'd do all this only after eliminating everything at idle - and if then still faced with only a "rolling miss" .
One thing I was curious about on your Sat am roadtest ; were you able to go thru 1/2 one time each w/o a miss of any kind ?
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"It pulled really nicely up to redline in first and second gears. Got it up to 5,500 rpms or so in 3rd, also looked good. It seems (I think) like it can take a little more throttle at times in the problematic 2,000-3,000 ..."
This was huge and even better if its held .
Would have been awesome to have had the VG on to see if it was "perfect" .
(Same deal with idle - when it was good) .
BTW , jeff , "good training" if nothing else to use your VG to check PCV , Backpressure , etc .
Larry Carley/ always good - I THINK "MOTOR" AUG2001 had a useable short articule on some aspects of VG testing .
This was huge and even better if its held .
(Same deal with idle - when it was good) .
BTW , jeff , "good training" if nothing else to use your VG to check PCV , Backpressure , etc .
Larry Carley/ always good - I THINK "MOTOR" AUG2001 had a useable short articule on some aspects of VG testing .
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" - At times it runs smooth under load starting around 3,000 rpms. Also, I sat and let it idle for several minutes at the end of the drive and the idle was smooth - none of the stumbles and hiccups that were present earlier in the week -"
See , that 3000RPM is huge also - because its probably? still in part 1 of VTEC .
( personally I'd keep doubling up on fuel additive -as needed - in the net 1.5-2.0 concentration range for 1/2 products )Just for s' and grins if unfamiliar with steam I'd probably soak the p*** out of the plenium behind the TB with TB cleaner - TRY TO BE "even coverage" , let it sit warm , not hot for 20-30 minutes and then drive it immediately hard .
See , that 3000RPM is huge also - because its probably? still in part 1 of VTEC .
( personally I'd keep doubling up on fuel additive -as needed - in the net 1.5-2.0 concentration range for 1/2 products )Just for s' and grins if unfamiliar with steam I'd probably soak the p*** out of the plenium behind the TB with TB cleaner - TRY TO BE "even coverage" , let it sit warm , not hot for 20-30 minutes and then drive it immediately hard .
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On my brother's 1997, the crank position sensor went out and it ran, but real rough. I know you haven't seen a code for this but it's just a thought.
The epic thread continues...
Today I cleaned off the IAC valve and fooled around with the vacuum gauge some more.
The little metal screen in the IAC valve was pretty clogged up. Probably 70-80% obstructed with hard deposits. I scraped 'em away with a screwdriver and reinstalled it.
Then I hooked up the VG and let the car run for a bit. The behavior was the same. Same general readings, same vibrating needle, same reaction to throttle inputs.
Took the car for a short drive to run some errands. No change! It drove great for a few minutes, then went back to it's misfiring ways. I've still managed to avoid tripping the CEL
jeff
Today I cleaned off the IAC valve and fooled around with the vacuum gauge some more.
The little metal screen in the IAC valve was pretty clogged up. Probably 70-80% obstructed with hard deposits. I scraped 'em away with a screwdriver and reinstalled it.
Then I hooked up the VG and let the car run for a bit. The behavior was the same. Same general readings, same vibrating needle, same reaction to throttle inputs.
Took the car for a short drive to run some errands. No change! It drove great for a few minutes, then went back to it's misfiring ways. I've still managed to avoid tripping the CEL
jeff
Already tried that, see page 4
jeff
Quote:
The epic thread continues...
Today I cleaned off the IAC valve and fooled around with the vacuum gauge some more.
The little metal screen in the IAC valve was pretty clogged up. Probably 70-80% obstructed with hard deposits. I scraped 'em away with a screwdriver and reinstalled it.
Then I hooked up the VG and let the car run for a bit. The behavior was the same. Same general readings, same vibrating needle, same reaction to throttle inputs.
Took the car for a short drive to run some errands. No change! It drove great for a few minutes , then went back to it's misfiring ways. I've still managed to avoid tripping the CEL
jeff
Thats another clue . If I remember correctly , from or near the beginning its ok that first start of the day .
Does it do that "all day long" - in other words is it just the first start of the day or does it have to sit for a while , and if so how long or is it more time than temp dependent ?
The reason to ask yourself that is you might get a direct or indirect lead on whats going on .
As an example , most EGR/EMISSION SYSTEMS have some sort of algorithim typically temp and or time dependent that they are "kept closed" to stabilise the idle .
Way back when , certain fuel systems would actually boost pressure across the injecter ,increase spark advance , etc , etc , - there are many things over the years that have been altered to promote "running" when "cold" , help develop heat esp for CC , etc - owners manual sometimes as well as service manuals should/might have details .( Don't forget idle speed , fuel/air ratio ie "rich")
Then again , could just be a fuel pump or regulator ,or injecter O-rings or ignition switch/ignition primary something or other that from a little bit of operation warm up enough to get "weak" or erratic - also could be software that ignores a sensor or has some fixed values regardless of sensor imput . etc , etc , etc .
Believe it or not the answer is probably somewhere in your thread .
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Where's Waldo?
The EX model doesn't have an EGR valve - amazing but true.
I only unplugged the forward O2 sensor. That's the one indicated by the code, and as I understand it the data from the rear sensor is not used by the PCM in any way. But heck I'm game for anything so perhaps I'll try unplugging 'em both.
g20ooh, the nice running at start up is definitely happening. I believe it has to do with the engine's temperature, as on these recent cold mornings I'll get 4-5 minutes of no problemo. If the car sits for a few hours, it'll drive nicely for a minute or two. If the car sits for a few minutes, it misfires from the start.
The Haynes book talks about how the engine runs rich for a while at cold start, and that it ignores the O2 sensor reading before it's warmed up. But the car acted the same with the O2 sensor unplugged so I'm not sure what to make of it. As you said it could just as easily be some part of the ignition system that acts up at a certain temp.
jeff
I only unplugged the forward O2 sensor. That's the one indicated by the code, and as I understand it the data from the rear sensor is not used by the PCM in any way. But heck I'm game for anything so perhaps I'll try unplugging 'em both.
g20ooh, the nice running at start up is definitely happening. I believe it has to do with the engine's temperature, as on these recent cold mornings I'll get 4-5 minutes of no problemo. If the car sits for a few hours, it'll drive nicely for a minute or two. If the car sits for a few minutes, it misfires from the start.
The Haynes book talks about how the engine runs rich for a while at cold start, and that it ignores the O2 sensor reading before it's warmed up. But the car acted the same with the O2 sensor unplugged so I'm not sure what to make of it. As you said it could just as easily be some part of the ignition system that acts up at a certain temp.
jeff
Quote:
The EX model doesn't have an EGR valve - amazing but true.
I only unplugged the forward O2 sensor. That's the one indicated by the code, and as I understand it the data from the rear sensor is not used by the PCM in any way. But heck I'm game for anything so perhaps I'll try unplugging 'em both.
g20ooh, the nice running at start up is definitely happening. I believe it has to do with the engine's temperature, as on these recent cold mornings I'll get 4-5 minutes of no problemo. If the car sits for a few hours, it'll drive nicely for a minute or two. If the car sits for a few minutes, it misfires from the start.
The Haynes book talks about how the engine runs rich for a while at cold start, and that it ignores the O2 sensor reading before it's warmed up. But the car acted the same with the O2 sensor unplugged so I'm not sure what to make of it. As you said it could just as easily be some part of the ignition system that acts up at a certain temp.
jeff
jeff ,
One way or another you want to take that manual and if not for a troubleshooting protocol then at least for system/component test information and start eliminating stuff . Unfortunately , although reasonable observation your last doesn't make anything clearer , - "perhaps" its a "little" less favorable to certain aspects of electrical if "small change" cooler ambient temps are extending the smooth running period -"large" .
I'd just start going thru the manual , focusing on certain fuel system and primary ignition/electrical ie fuel pump , fuel pressure regulator , and ignition switch to coil including grounds . I still don't know if you have an integrated coil ignitor module and a separate ignition command module or something else by description but the concept is anything on the primary side whatever that really means .
Its just a hunch at this point , but I'd get fuel pressure ie pump and regulator known to be good by fuel pressure measurement and electrical measurement as needed . This does not finish off the fuel system but it does take you as far as you probably want to go there.
I'd then switch systems and get the ignition switch . At this point , you certainly could reverse that order -its good either way .
The idea is something like this .
If you can't nail troubleshooting charts then go after systems .
If you can't nail systems then you will have to grind it out on components and although typically less efficient you are learning here and as always moving the elimination ball forward .
Personally based on how well it ran temporarily after you added the TECHRON/FP "superstrenght" formula with a full tank of good fuel and cleaned the throttle body you could consider almost duplicating that . See above previous post on soaking past or behind throttle body area .
Maybe if you wanted to try something more out of box you could see what happens with a new O2 sensor although if that didn't change anything I'd probably want to put the old one back in until everything was settled down .
Do one thing first that will payoff big now or later .
Before you change anything up Put the VG on before you start cold ie install before and read during a cold smooth start situation and see what it says . Stay on the gauge until it starts to go rough . In other words , you really do want to know as compared to previous miss situations are there 0,1, or 2 swing actions present and if so how they present during smooth operation thru the transition to "miss" .
Come to think of it , this is a really good idea . If you get nothing else out of this post or just don't want to do much more then focus on this .
Let us know what happens .
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jeff ,
Pretty sure this is at least part of your problem ie sit of pants miss - on the VG the 1/4 -1/2 drop - (if you have one) .
Fast Idle Thermo Control Valve . Sometimes labeled "FITV or FIV ETC Look in your manual - very easy to test .
It fits (everythingx2) and it is a very common problem .
"Odds" are yours is either shot or dirty .
This involves your second port down ie #2 0f 2 in front of throttle body .
Crude test ; remove air filter intake tube ( engine warm and "missing" . Put your thumb or finger over that port(hole) see if you can feel suction .If you can you have a problem here . Also note if miss reduces or goes away . Personally I would have the VG hooked up and observe that as well .
Pretty sure this is at least part of your problem ie sit of pants miss - on the VG the 1/4 -1/2 drop - (if you have one) .
Fast Idle Thermo Control Valve . Sometimes labeled "FITV or FIV ETC Look in your manual - very easy to test .
It fits (everythingx2) and it is a very common problem .
"Odds" are yours is either shot or dirty .
This involves your second port down ie #2 0f 2 in front of throttle body .
Crude test ; remove air filter intake tube ( engine warm and "missing" . Put your thumb or finger over that port(hole) see if you can feel suction .If you can you have a problem here . Also note if miss reduces or goes away . Personally I would have the VG hooked up and observe that as well .
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Evidently there are more than 2 possibilities with this FITCV OR FIT OR etc . They can get "loose" internally and some other stuff that you can repair - don't have to replace necc .
Here is a link that has great pictures - make sure you read all of part 1&2 - don't stop at the first 3 posts . I put this one here because of the great pictures . Now that I've read more about its conceiveable with the right kind of problem here it could show as either needle fluctuation .( I'd still get the gauge when it runs right etc before doing this . Just add http://www.
superhonda.com/forum/showthread.php?t=259965
BTW , Ground problems on this car have been positively identified with fuel and primary ignition problems and a sort of "sluggish" running as well .(Three grounds in particular) .
Given the amount of corrosion on your distributer body in your pictures I'd plan on cleaning up your grounds one way or another . Tap and Die etc . Whether or not it solves any problem directly its easy to do and you're going to need it sooner or later .
Here is a link that has great pictures - make sure you read all of part 1&2 - don't stop at the first 3 posts . I put this one here because of the great pictures . Now that I've read more about its conceiveable with the right kind of problem here it could show as either needle fluctuation .( I'd still get the gauge when it runs right etc before doing this . Just add http://www.
superhonda.com/forum/showthread.php?t=259965
BTW , Ground problems on this car have been positively identified with fuel and primary ignition problems and a sort of "sluggish" running as well .(Three grounds in particular) .
Given the amount of corrosion on your distributer body in your pictures I'd plan on cleaning up your grounds one way or another . Tap and Die etc . Whether or not it solves any problem directly its easy to do and you're going to need it sooner or later .
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