Nobody can figure this out

This is for a 2002 Honda Accord, SE 4 Cyl.

For over a year I have been getting a CEL for a misfire of Cylinders 1 and 2. I did a standard tune up, Changing the spark plugs, wires and distributor cap, but to no avail. Having reached the end of my knowledge, I took it to the Honda dealership to see if they could fix it. They told me it was the ignition coil, so I replaced the coil. That didn’t solve the problem so I brought it back to the dealership, which proceeded to tell me that I needed to use Honda spark plug wires and distributor cap. They replaced the wires and cap with Honda parts and told me it was fixed. On the drive home, I noticed the misfire again. Back to the dealership. 2 weeks later I finally get sick of waiting and go pick up my car. Here’s the list of things they claim they tried:

Compression Check
Sea Foam
swapping fuel injectors
changing the distributor

After none of these things worked, I decided to take the car to another mechanic, who told me that the distrubutor and EGR valve needed replacing. They assured me that that was the problem, but after that didn’t work, they still charged me to adjust the valves.

Later I tried changing the PCV valve, now losing hope that anything would work…and no, that didn’t work.

Strangely enough, as winter rolled around the CEL went off, and the car misfired much less.

Now summer is back, and so is the CEL, and I’m hoping somebody here is smarter than the mechanics around here.

Please Help


Did the dealer provide the actual values for the compression check?

Dry and wet for all 4 cylinders

Did they perform a complete fuel pressure test?

Or just swap injectors?

Did they perform an injector balance test?

Has anyone hooked up a noid light to verify that the injectors are in fact being pulsed by the PCM ?

Has anyone gone to the trouble of checking and adjusting valve lash?

Even if the valves are NOT noisey.

Valves that are too tight will make NO noise and will burn

On an off note, it sounds as if the Honda dealer owes you some money back.

It sounds like a problem was discovered with compression and this led to the valve adjustment.
If the compression was down on a few cylinders due to tight valves then it’s quite possible that adjusting the valves properly will either not cure the problem or it will be a short term fix. Tight valves (especially exhaust) may cause valve face and seat burning that may show up immediately or it may not surface for months or years later.

If valves were tight then a second compression test should have been done after the valve adjustment.

Writing down compression numbers and notating which valves are tight, if any, on the repair order is a must.

An intake manifold leak will cause the computer to give a misfire code.

How is the idle. Is it smooth and around 750 rpm? Is it rough and around 750 rpm or is it rough and above 950 rpm? Is it smooth but gets rough as you accelerate through certain speeds or at certain RPMs?

The clue you left me with was the TEMPERATURE clue…when I hear things like “I dont get a misfire as much or not at all when it is cold out” Tells me that the issue resides in an electronic component…Heat will suss out a failing or cracked electronic ignition component…Heat will always make it more apparent. When the electronics that are failing are heated up they exhibit their failure mode MUCH more readily…

I would say…that after all of your repairs you have had done…I would look at the distributor ITSELF…it may be on its way out… You can find one new or fully rebuilt online for 150 bucks or less… and just install it yourself…I bet that solves the problem.

The other item I would look toward is the cam or crank angle sensor…either one may be failing. In your Honda You may not have both of these sensors…they may be located inside your distributor.

I bet that distributor is your culprit…and its so cheap to swap out with a new one…You should honestly change this out. I’ve faced similar “difficult to solve” misfire issues in many Hondas …and we always seem to solve it by changing the distributor itself…after swapping the obvious and cheaper parts FIRST…but for whre you are with this? Do the distributor…you will be happy that you did. Bet it fixes you right up.


I don’t think Honda blackbird has ever been wrong when it comes to Hondas.

Like Bing, I think Honda Blackbird is right. I had the same issue on my 99 Accord and a quick distributor change fixed the whole thing (although I also changed cap, rotor, plugs and wires for good measure). One thing I will say is that ignition parts should always be replaced with OEM parts or high quality aftermarket parts. Cheap ignition parts are the source of endless misery in Hondas.

Honda has my vote too. Specifcally, the Ignition Control Module in the distributor would be my suspect.

Diagnosing this isn’t difficult with a scope, but it seems that when dealers get older cars they choose not to bother with any real diagnosis. Perhaps they hope the owner will spring for a new ride.

The OP says that the 2nd mechanic replaced the ditributor and egr valve

Did he replace the whole distributor or just the cap. I believe these are separate parts and might be worth looking at the receipts to double check if the cap and rotor were replaced oui the whole distributor.

Seriously do not think it is the distributor. Its two cylinders that are misfiring so you can rule out anything that affects all four cylinders equally. That leaves plugs, wires, distributor cap, valve lash and compression.

Two cylinders side by side often mean a breach in the head gasket between the cylinders. No water jacket at this point so only loss of compression between the cylinders. Second choice would be valve lash or defective V-tec rockers.

Keith, in this setup the distributor does control when and where the spark goes off . That’s why I suspect the distributor.

Mountainbike, sorry but that is not quite so. The when is controlled by the computer, the where is controlled by the rotor and distributor cap. The cap is the only part that can affect the cylinders differently.

The ignition module gets it firing signal from the computer, there is no reluctor in the ignition module. The CYP uses lines on the distributor shaft as a cam position sensor so the ECM knows the exact position of the crankshaft and the CPK tells the computer the crankshaft speed. The computer then uses this and a bunch of other info to determine when to send the signal to the IM.

I guess its possible that the distributor shaft might be contaminated so that the CYP doesn’t work part of the time, but she did say that the dealer already tried a new distributor. I really think a cylinder leak down test will reveal a breach in the head gasket. You know I don’t jump on head gaskets lightly like a lot of people here do.

Ouch! I stand corrected not only in the system but also in that I missed that a new distributor was already tried. I need a moment here to remove my feet from my mouth.

Thanks Keith. You’re a good man.

Has the crankshaft position output signal been monitored?

Thanks for the suggestions guys. To answer your questions:

db4690 - They did not give me the actual values for the compression check that they claim they performed, when I asked the mechanic that performed the test was not there, so they called him and he said it was normal. I will be doing another compression check this weekend to see if that solves the problem. As far as a fuel pressure test or an injector balance test, I assume that it was not performed as they didn’t tell me about them.

ok4450 - The valve adjustment was done by the second Mechanic, and as far as I’m aware he did not perform a compression check. He did tell me that the valves were off on cylinders 3 and 4, but 1 and 2 were fine.

keith - The idle is rough, but the roughness varies. sometimes it idles very rough, and sometimes the not nearly as rough. It doesn’t seem to correlate with engine temperature or outside temperature either. It seems very random. At higher RPMs it is consistently smooth.

Honda Blackbird - The whole distributor was swapped with a known working distributor at the dealership, and then the second mechanic replaced the distributor with a new part. I do not have the old distributor, but the mechanic did mention that the distributor was full of oil. As for the temperature change, I’m not sure if it was actually due to temperature, as in the winter the problem was gone even on warmer days, and in the spring/summer, it has been apparent, even when it was snowing outside. I live in Utah, it snows in the spring, the day after a 70 degree day. it’s weird. Is it possible that the winter mix fuel helped the misfire somehow?

Again, The whole distributor was changed, not just the cap.

As an update, I just had my codes read and the misfire is now in all 4 cylinders. I will post the values for my compression check once that is done.

Have you had the timing belt serviced in this vehicle, and if you did, did the misfire start occurring just after it was done? If so, I would now suspect that the rear balance shaft was not timed correctly. Not every mechanic knows how to get this correct.

Regarding compression testing, a relative compression test can be done with one of the diagnostic testers available from several manufacturers. An old Sun tester and also the Sun Vantage, as I recall could give relative compression

and if a cylinder was significantly weak an actual physical test would be done there. The video shows the starter amp draw test which is the quickest. A cylinder power balance test on a running engine was also quite good. If all cylinders were similar a physical test was not necessary.

keith - No I have not yet had the timing belt serviced.