Hitlayers

What's up fellas, ,u car is biting right now, from my past experience it's either a spark plug or ignition coil, since the the spark plug or ignition coil has not gone completely, is there any way I can find out which one is failing? Usually I wait until the coil fails completely then you can tell by doing the test to see which plug does not give you a spark but in this case it's becoming annoying since it's biting but has not failed completely.

Just want to know how to find the bad one before it fails completely.

Any help would help.

Thanks,

Skirmich

You should use a Volt-E-Meter to check the Coil Resistance between the Six find the Average and the one failling well be the one with More Resistance.

01tl4tl

are you on the single coil or 6 coil ignition?

pull a plug and inspect wear
are you running the correct ngk?

3.2TLc

Hey Hitlayers, U car is biting right now ?

Most of the time a bad coil will cause a "CEL". If it's been awhile.....replace the plugs with NGK's. When was the last time that the EGR passageways were cleaned ? Could be a restriction in the fuel system.....maybe an injector ? Start with the basic stuff first !

Skirmich gave some good advice on checking the coils.

01tl4tl

get the codes read --never trust a CEL as your indication of fault codes

pull a plug for wear/age check

if 6 coil system: unplug power lead at coil, rpm drop = good coil
no rpm drop = bad coil
try holding rpm at 2000 if unsure--will show under load

Skirmich

Hey that Method seems Legit 01tl and Easiest compared to check for Resistance... To OP, do what 01tl4tl said!

Hitlayers

Thanks for the replies guys, I definitnely know it's one of the coils, I've felt this before, I just usually wait for one to go then I do the test where I pull out each coil with spark plug and ground it to see if I get a spark, right now i'm getting a spark from all since the bad one is not completely gone, was just trying to see if I can find out the bad one before it completely goes, I've inspected each one, cant tell which one is the bad one......CEL is not on either...

3.2TLc

Hey Hitlayers, the method which you described for testing coils by pulling them along with the spark plug.....then grounding the unit is not the simplest way to check the coil. Our TL plugs and coils are very sensitive.....avoid over-handling them or they can be damaged.

I've found 01tl4tl's procedure to be an easy and quick way of determining which coil is malfunctioning. With the motor running, simply pull the connector off of each coil.....one at a time.....until you notice a difference in the way the motor is idling.....if it wants to choke, coil ok ! But if it stays the same, ya got it ! Replace that cylinder's coil and reset PCM afterwards.

But Skirmich's suggestion of using a meter to check continuity and voltage will give a more accurate comparison of the coils.

Hitlayers

Thanks guys, all advice appreciated and very helpful.

fsttyms1

This method only works on a coil that has failed. Many times it is still working just not the way it should and the best method is to buy a new one and slowly start swapping it from one to the next till the issue is solved.

The other possibility of issues are a fuel injector not working properly.

01tl4tl

but hey- the customer is certain its a coil-- so lets replace all 6 to validate their findings/feelings!

then do a diagnostics to find what is really wrong

with our high energy system, I would not be pulling the coil and plug together to test-
its not a 65 chevy!!

Hitlayers

Not 100% but it's something I felt before, I don't claim to be specialist.....

Just asking for opinions......

3.2TLc

Yeah man, sometimes ya gotta bite it and take it to a real pro for diagnostics !

TLer trash

One more opinion. I've tested literally tens of coils with an ohmmeter. I've yet to find one outside of factory specs. Typically coils will fail only under load at first. Swapping a new coil cylinder to cylinder works, but if you have a helper to carefully apply the throttle with the car in gear, you can disconnect them one at a time to isolate the bad one. If you can't duplicate the misfire consistently by brake torquing it, don't do it. Also, don't do this for more than about 10 seconds without putting the trans in neutral for about 30 seconds at 1500 rpm or so. This is to keep from overheating the trans fluid. If you have to apply more than 1/4 to 1/3 throttle, forget this method: applying much more throttle can be dangerous, and harmful to our gossamer transmissions.

01tl4tl

pay for diagnostics! thats what we are for!!
that 150 bucks will buy 1 coil, a set of plugs, and some seafoam!!!
that will fix most things~!

codes man- its all about the codes
try pushing the car harder if no codes yet,,make the prob show itself
above 2k,,above 4-5?