Hey all. I have been reading the forum and decided to join up and become a part of the Acurazine community. I just have a quick question about the ignition coils. I have been experience the effects of the engine misfires (shakes, low rpms, sluggish respone etc) pretty convinced it was the spark plugs. Changed them out no difference now im sure its the ignition coils. How can I tell which are bad? I saw a post where someone said pull one at a time and replace with a new one to find which is bad, but what if 2 are bad or even all 6? Any suggestions will help! Thanks in advanced and I look forward to someday helping some guys on the forums

 

while your engine is on and idling, pull the coils out one at a time. then, look to see if the rpms change after you pull it out and if they do they are still good. however, if you pull it out and nothing happens to your rpms meaning it stays the same with no movement then that coil is bad. i used this same technique and saved so much money because i had the same problem awhile back and found out i only needed to replace one coil instead of all 6. good luck! hope it helps!

 

hey I appreciate the response! When i took it to my local store they said all cylinders were misfiring so ill pick up a coil tomorrow and check it out. Thanks again

 

A: exactly what spark plugs did you install- the correct 8$ each ngks, or something else?
wrong plugs make it run really bad in a hurry

B: bad coil will show a CEL dash light - then you get the codes read at parts store
If it says multi cyl misfire its probably 1 coil

while its possible for 2 to go bad- most often the failure is related to mishandling of coils during plug change!- set then down hard and a month later~

for all 6 to go out would be higher odds than winning the superlotto twice,, in one day!

whats the current miles? over 100k- Im thinking you need to do the egr port and passage cleaning of the intake manifold
and service/clean the TB-iacv while you are there
egr port clogging causes miss at idle and other problems
that should be cleaned every 75kmiles and is not found in any book info to do

another strange thing is broken front or rear motor mounts- they are vacuum boosted and if bad,, they leak their oil filling and vac leak.= mystery problem

 

to clarify-= do NOT remove the actual coil from a running system or expect the last shock of your life~
just its power lead is all it takes

after new coil install, reset the ecu by pulling CLOCK fuse on passenger end of dash
Drive car- get codes ckd again

 

I did buy the NGK plugs and I was aware of handling those coils and the plugs as if they were glass or a light bulb. The CEL does flash and i step on the gas sometimes it moves sometimes it just sits the and the RPM's rev. The EGR valve was cleaned last year. The car is at 166k miles but did have its 105k service. Ill check one by one if the coils arent the problem then ill post back tomorrow. I recently moved from Miami to Orlando Florida and before I drove it up there was no problem, afterwards I noticed the jerking and thought transmission. It got progressively worse over time. Maybe that can help some. Also sometimes it moves pretty easy especially after the spark plug change but most times just sits and revs then decides to move when its ready

 

so just remove the the plug that goes into the coil not the coil itself with the engine on, correct?

 

Correct. Just the connector to the coil not the coil itself reffering back to 01tl4tl's post.

 

so what NGK plugs are we suppose to use?? please provide part number thanks!

 

NGK iridium ix. Sorry i dont have the part number off the top of my head maybe someone can chime in.

 

depends on type S or P engine
ask parts counter for plugs for an 04,,irids were stock on them

 

with CEL you get fault codes- go to a parts store for that-ask for a code scan
its free
those will help us diagnose your prob

 

egr valve cleaning is one thing--the complete removal of intake manifold and clean the egr passages and ports,, that is needed every 75kmiles
so you are due for it again even if done right before--clogged system causes strange problems
if one of the codes is egr lift or similar = system clog

 

Bemo
I would go ENGINE OFF to pull electrical connector
Do you understand about YOU being the path of least resistance to ground?

 

That's ridiculous! The whole point of doing it running is to feel as each cylinder drops. There is absolutely no danger of electrocution, shock, or so much as a tingle unless you lick the terminals.

 

alright guys, I have an update! checked it out using the methods here and I found 1 in the front and 2 in the back that made no reaction to the pull so I have 3 bad coils! it is pouring in Orlando right now so I will have to change em out tomorrow. I'll give another update tomorrow once its changed out.

 

dont think you have 3 bad coils--that would be very odd to all go at once
buy 1 and try it on each cyl you suspect- reset ECU each time

my concern with hot swapping the connector is not gettring it back in fully, will cause further bad diagnostics

 

That's unnecessary. The connector to the coil supplies the PRIMARY of the coil. High voltage is present on the secondary side, connected to spark plug.

OP: "...but most times just sits and revs then decides to move when its ready"

In gear, the engine revs up but the car does not move?? Sounds like transm. trbl. to me, in addition to misfires. Fluid level ok?

 

thanks for the correction totalled- I worry about electricity-
had a bad experience when I was young- found a hot wire still hot--ooops,,

the main thing on this test would be getting the plugs back in tight

I would swap a few coils around to see if the ecu code follows them
remember to reset ecu