Check your coils. My mechanic was inspecting my 4.5 y/o 02 TL-S w/ 76K miles and noticed that one of my coils was bad and was causing a misfire on one of my cylinders! I wasn't even aware of this. So here's something else to check other than the infamous "bad actuator."

 

Wow I find that surprising. If the coil was indeed bad the check engine light would be on and you would certainly have noticed it.

I had one go bad a few months ago and I immediately knew something was wrong.

What did he do to check that the coil was bad?

 

The J32 engine design is a bit unique compared to other traditional engines. From what I understood, each cylinder uses a coil to fire up the individual spark plugs. I didnt see what he did, but it does require a bit of work to get there. My check engine light was NOT on for some odd reason.......

 

Um yeah I know how OUR engine is designed. Like I said, my J32A1 (basically the same as you J32A3) engine had a coil pack go bad a few months ago and there was an immediate indication that something was wrong. I would ask him for the old coil pack back.

I can email you some instructions from the Helms manual to test to see if it's really bad.

 

Nsxnext is right. If one of the cylinder is misfiring, the crank angle sensor will detect abnormal rotational speed, and turn on the check engine light and store the related trouble code inside the computer. There is no way the OBD-II spec computer will have missed it, because any cylinder misfiring will bring up the emission level.

 

I'm not buying a bad coil that the OBD-II just over-looked. It comes on when you don't tighten your gas cap good enough (I know because mine is on now for that), it's certainly not going to miss something like a misfiring cylinder due to a bad coil.

 

How well do you trust your mechanic?

 

He's my uncle and I'm just paying for the part from Acura.

 

Maybe its bad, but not bad enough to cause the check engine . Like its not putting out the voltage as it should be. Say for example its only putting out 5v instead of 10v. SO the cylinder will still fire and get it going but not as aggresive spark it should be getting to make full power.

Coil are pretty easy to test, use a multi-meter and test the ohms. I dont have the helms to know exact what ohms it should be at but they are all should be in the same range

 

you might want to get a second advice, cuz a bad coil would definitly have thrown a CEL.

trying to save $$ by asking your uncle is one thing, but replacing parts that were not the problem in the first place is another.

 

THIS IS EXACTLY WHATS GOING ON! I should have clarified my original post.

 

But that's exactly what would kick out a CEL. Not burning fuel efficiently.

 

In theory, yes. But in reality,with a "partially bad coil" it does NOT (well at least in my case). I simply started this thread to make others aware of a potential issue.

 

I'm really interested to know how your uncle can pick out the "partially bad" but not bad ignition coil. It must have taken years of experience to do that.

 

The OBD-II system is so extremely sensitive. I'm just not buying into this. If you tighten your gas cap, but don't "click" it, it can pick up on the small amount of fuel vapor that could escape into the atmosphere - BUT, it can't pick up on a coil that's causing problems with the engine's power and efficiency? Sorry, but that's

Edit: The CEL will flash when misfires are occuring, has that happened?

 

Solid CEL means some emission-related component(s) is not functioning properly, but can wait. But flashing CEL means immediately attention is required, or else it will cause damage to other components (especially catalytic converters).

 

i had a coil changed about a month ago.. car was shaking like crazy and my check engine and TCS were on

 

In theory, but not always. It is possible for one to be going bad and not thro a code. My buddy and i just changed them on his maxima(car just wasnt running properly but no cel) with 60k on it and it made a huge difference. I saw it on my S10 too. Over time they loose the way and the amount of spark they are able to produce. Im sure if i changed them on my car with 191,192 miles i would see a difference.

 

Stronger sparks sure make a difference in performance. That's why racers upgrade to MSD ignition coils and performance spark plug wires, but there is nothing for our DIS cars. But weak sparks are not the same as mis-firings. Mis-firing is spark when no spark is needed, or no spark when spark is needed.