Hey guys,

I have a 2003 Honda Civic EX with ~178k miles, which ran perfectly fine before I dove into replacing my timing belt, tensioner, and water pump. Now, it idles fine but stumbles under load. I had the codes ran and they came back reading random misfires. I have done a few quick searches and have turned up a rash of information. What I am asking from you is a comprehensive checklist of possibilities causing the random misfires.

The story:

…it was about time to replace the timing belt. Using multiple write-ups around the Internet and my dad whom successfully performed the same job on his 2002 Civic weeks earlier, I felt confident in tearing my Civic apart.

Everything went well, we had no issues performing the job in a single evening. We were very adamant about lining up the timing marks on the crank/oil-pump and the cam "UP"/cylinder-head dash-marks. We turned the engine over by hand, making full revolutions without coming across any binding.

After buttoning the engine up, we filled it with fresh oil, coolant, and rechecked all our bases. Then, we confidently started it...

...it ran great.

I took the car for a test drive around the neighborhood, and it drove well for over a week. It seemed to me it was running smoother than ever. Then, it started to stumble. The misfiring was obvious, we took it to the nearest auto parts store and had the codes checked. The codes that were ran at the auto parts store showed random misfires on all cylinders.

The next step I took to fix the problem was cleaning some dirt/grease found around the coils and plugs. This may have helped tremendously with the "stumble" and seemed to smooth out the misfires. However, my clutch failed in the process of testing

Could anyone help me by putting together a checklist to pin point my random misfires.

1. Compression should be even across the board. The numbers will vary depending on the engine but as long as they are all close and not ridiculously low your okay.
2. Not sure.
3. If it was the coils you'd know it. The car would stumble a lot and hardly run. These parts also very rarely break down. Especially four at once.
4. These sensors would toss you a CEL.
5. Timing belt shouldn't lose its alignment after it's set unless something is very wrong with the install.
6. My input? Recheck your work. Remove the upper timing belt cover and make sure nothing has happened. You should also check to make sure the timing belt hasnt skipped a tooth or two.

If it drove fine for a week after the timing belt job, this is quite likely a brand new problem.



Post the actual code number(s) and the freeze frame data.

Yes because we can all post freeze frame data.

Where were you on that one BlueEM2?

It's a legit request.
I think all but the cheapest of the cheap code readers will give the Freeze Frame data.

My code reader does not just freeze frame data. It freezes time

Oooooh that sounds powerful. I hope you use that power for good, not evil.

Unfortunately, the car isn't in front of me ATM

Will a moderator please delete this reply as well as a few of the previous?


I was actually seeking information on some mechanical excellence of any kind. Based on my previous request, If you could kindly remove yourselves from this forum so that it can be used for future mechanical problems it would be greatly appreciated. I feel confident that I am speaking for myself, as well as others that may have a similar problem in the future. Thank You for taking the time to solve my current issue, but I would rather take it from here on my own. Keep posted for positive results if anyone is interested.

Sincerely,

G.Verner

I know bud. It was really directed at BlueEM2. It was in reference to his earlier post with the flakey ttl guy and his issues.

any thoughts on your spark plugs, by any chance? new? 1/2 life? long time ago?
understand you did not do a head gasket, but i did and they got dirty during the job, so i changed them anyway, so just a wild guess.

my guess is your belt is loose and has jumped/skipped a tooth....

i would start by pulling the top timing cover and rechecking the timing marks....

did you use the grenade pin method when torquing down the tensioners bolt?

there is a specific method that must be followed....

with the belt off, the grenade pin installed, and the spring installed on the tensioner ONLY....

1- install tensioner and tighten bolt just snug
2- loosen the tensioner bolt half turn
3- install timing belt
4- install tensioner spring
5- turn crank by hand two full revolutions
6- check timing marks
7- repeat 5+6 one more time
8- tighten tensioner bolt and torque to spec
9- remove grenade pin

did you follow this procedure? if not, you need to rip it all apart again and reset the tensioner using this procedure....did you use a torque wrench on the tensioner bolt?

there is too much of a coincidence here....you had a fine running car, then you did a major repair, and now a week later you have a serious problem?....hhhmmmm.....if i was a gambling man, i would bet my house it has something to do with the repair you performed

Can't you help someone resolve their issues and have a little bit of fun at the same time too? Didn't realize that life was this serious.

Ermmm, AFAIK these will shut down at 2 seconds if the cam-crank relationship is out of sync (timing belt skips a tooth).....True or false?

If it did actually continue to run with the belt a tooth off, it would just be a bit low on power and possibly set codes related to that.




OP described what sounded to me like a cylinder miss under a load:
Does it misfire sitting still and revving the engine?
Does it ONLY miss while driving? Full throttle? Steady speed?

What? What?

im aware of the 2 second shut down....but i have also witnessed these engines continuing to run at one tooth off, so im sticking with my original guess

You have witnessed this on a 7th gen?
(Just to clarify here, since I did ask earlier.... On a thread somewhere.... Was it here? Did it get removed?)



2000 and earlier will run a tooth out, the PCM does not judge cam-crank sync on those.

yes i have seen (with my own 2 eyes) a 7th gen run one tooth off without shutting down

Ok cool. What year car?
I'm trying to figure if it applies to the whole generation or if there was a programming change somewhere in the middle.

See, I just know what I have seen. I didn't recall ever seeing one still running with only one tooth off, but then I normally don't get to see/deal with the broken cars until there is a huge problem.

I have never seen this phenomenon documented in print on the Honda site, but my experience with other manufacturers leads me to "think outside the box" at times.

it was either 04 or 05, cant remember exactly, but definitely one of the two, 1.7 non-vtec, not that it should really matter

I'm having the same problem with my 97 civic but I haven't changed the timing belt I have changed the spark coil I Jerry rigged it by turning the idle up what should I do to fix it