Hi, I have Honda Jazz 2007, 200k KM mileage. My car ignition coil last maximum 6 months and after that it requires replacement. Whenever it happens, my car misfires only while driving. There are no any symptoms like rough idle, decrease in car power, poor fuel economy, difficulty starting the engine, check engine light, exhaust backfiring. Only car misfires while acceleration in driving. Even OBD device doesn’t show any error. I’ve replaced new plugs but still facing same issue. Whenever this happens, mechanic suggests me to change the whole coil pack because mechanic unable to find which coil is bad.

The only way for mechanic to find out, when car misfires on idle position. And this only happens when I don’t replace the coil and use my car for long time with bad coil (which is not practical). Please guide how can I fix this issue or at least a way to find out which coil is bad.

 

A misfire should send a code and light up your Engine light. It will tell you which cylinder is misfiring, If it is a random misfire it may be something more than a coil pack or plug. Try a different mechanic if this is what they are telling you. When I had a misfire even with the light on it did not perform abnormal either.

 

Ageing spark plugs can certainly cause coils to fail, so replacing those is a good move. There are also potential issues with interference on the crankshaft position sensor wiring due to plugs/coils going bad; see this page on Springbok Photography and this article from TiePie automotive. This won't necessarily set error codes or light the Check Engine light. You can potentially re-route the crankshaft sensor wiring away from the ignition coil wiring to improve the situation (see the Springbok Photography article).

I also wonder if the hot conditions in Dubai might cause premature coil failure. When replacing, be sure to use real, actual, genuine Hitachi or NGK parts.

 

Coil are essentially simple potted transformers from 12 to thousands Volts. It's extremely improbable a trafo gets damaged unless overheated. But the pin/springs mechanism in the coil pipe can be affected by corrosion. I would inspect and try with cleaned ones, look at the spark plugs as suggested and be sure to not let them loose. I just fixed bad misfiring in my 2007 Jazz which had no whatsoever CEL on dashboard...

 

It mainly breaks through the rear row of coils, it is very easy to determine: When you turn off a good coil, the engine does not work stably, when you turn off a faulty coil, nothing in the engine will change.

 

You need to adjust valves and change coils . That’s what i found on some forums.

 

share here what kind of spark plugs were used and coil part number too

 

Replace the cover valve seal. Its oil leaks to the spark plugs that caused you loose power.

 

Dude! I have the same issue... I haven't read all comments but have you resolved your issue!? I hope you are still following your post.
Mine stutters on gear changes and when accelerating harder and after putting in neutral rpms fluctuate till smooths out eventually.
Checked coils by unplugging, no faults, changed sparks, gearbox and engine oil, running on premium fuel. Don't know where to go from here... Some suggest trying new coils but for trying is expensive and clutch plate same thing... P. S Some suggest always that we should see engine management light apparently on hondas it can never happen as its not so sensitive and might not throw a code.

 

If you are unwilling to buy coils to test, then remove coil and clean up. the coil and boot can be seperated by simply pulling them apart. remove the spring and clean any rust or oxidized residue that will be there. the end of that spring has contact point, which may be pitted/oxidized. get a fine sandpaper and smooth out oxidation/pitting to get better contact.
spray down inside of boot and ignitor with maf cleaner to remove oil and oxidized residue. take note of any damage or deuteriation of boot or ignitor rubber, that may cause arcing and cause misfire. hopefully this will help. FYI this cleaning may prolong life of old ignition coils but its not going to "make it new", you will have to replace it soon anyways but this may buy you alittle more time.

 

Problem is I'm not entirely sure are they coils, many people, many opinions suggested to my problem... And don't even know where to take it to Honda to rip pants or some independent garage.
I realised after mine is GE 2013