ignition coils re-visted
Thread Starter
Heel & Toe
Joined: Aug 2001
Posts: 18
Likes: 0
From: libertyville illinois
ignition coils re-visted
i searched the archives and couldn't find a way to individually test these coils.
Does anyone know any tips. I just has a repair shop (not dealer) tell me that they agree the car is misfiring and has some real rough ranges etc. and
that the coils may be bad (some or many) . The flowchart from the service manual ends up either at customer complaint not verified or replace coils.. they must be working correctly MOST of the time but couldn't one or a few be weak/intermittent?
pardon the edit, but i wanted anyone who responded to the recent plugs vs. idle post to perhaps see this as well.
john
Since i don't have any real codes set - just migrating misfires that may not be really assigned to the cylinders indicated etc.. the dealership says vehicle is operating within specs - i of course do not agree though it may be true!
please help.
thanks, john
[Modified by jfc33, 8:16 PM 7/3/2003]
Does anyone know any tips. I just has a repair shop (not dealer) tell me that they agree the car is misfiring and has some real rough ranges etc. and
that the coils may be bad (some or many) . The flowchart from the service manual ends up either at customer complaint not verified or replace coils.. they must be working correctly MOST of the time but couldn't one or a few be weak/intermittent?
pardon the edit, but i wanted anyone who responded to the recent plugs vs. idle post to perhaps see this as well.
john
Since i don't have any real codes set - just migrating misfires that may not be really assigned to the cylinders indicated etc.. the dealership says vehicle is operating within specs - i of course do not agree though it may be true!
please help.
thanks, john
[Modified by jfc33, 8:16 PM 7/3/2003]
Thread Starter
Heel & Toe
Joined: Aug 2001
Posts: 18
Likes: 0
From: libertyville illinois
Re: ignition coils re-visted (jfc33)
also wanted to add that i have scanned and logged many runs etc and
used the flasher type inductive coil pen devices and couldn't tell much...
jfc33
used the flasher type inductive coil pen devices and couldn't tell much...
jfc33
Drifting
Joined: Sep 1999
Posts: 1,908
Likes: 0
From: Manassas, VA, USA
Re: ignition coils re-visted (jfc33)
Try the "poor man's oscilloscope" trick. Take a timing light and clamp it over the plug wire, then shine the light on the hood. If it's missing, you'll notice the skip in the blinking pattern. Do it on each spark plug to find which is/are missing.
It's a tedious, but useful technique. Not optimal, but these coil-near-spark systems don't seem to be compatible with oscilloscopes - the local community college has a $50,000 computerized scope, with the individual pick ups for each coil, but the pattern it picks up is just weird. We called the scope manufacturer (Sun) and they told us that's just the way those systems are.
Good luck. :cheers:
It's a tedious, but useful technique. Not optimal, but these coil-near-spark systems don't seem to be compatible with oscilloscopes - the local community college has a $50,000 computerized scope, with the individual pick ups for each coil, but the pattern it picks up is just weird. We called the scope manufacturer (Sun) and they told us that's just the way those systems are.
Good luck. :cheers:
Thread Starter
Heel & Toe
Joined: Aug 2001
Posts: 18
Likes: 0
From: libertyville illinois
Re: ignition coils re-visted (lyonsh)
thanks for the suggestion - I will flash each wire again and see if anything interesting shows. I wonder if those exoensive SUN scopes etc. can be used in a one cylinder at a time mode? My local shop apparently was able to see some firing that was or wasn't occuring on theirs... Maybe all they were looking at was the weird pattern you describe that is probably mostly trash.
(unable to see burn time,KV etc...)
BTW anyone have any luck with an ordinary analog scope in single cylinder type of examination?
(unable to see burn time,KV etc...)
BTW anyone have any luck with an ordinary analog scope in single cylinder type of examination?
Drifting
Joined: Sep 2002
Posts: 1,529
Likes: 53
From: Houston, TX
Re: ignition coils re-visted (jfc33)
On older cars you check the coil condition by measuring resistance in the coil. I'm not sure what the LS1/LS6 coils should read, but at least you could compare them all to each other and find the weak one(s).
Also, I would think the plug wires or plugs would be more likely misfiring than the coils. Especially the plug wires.
You may also have a cracked coil housing causing the spark to jump.
Also, I would think the plug wires or plugs would be more likely misfiring than the coils. Especially the plug wires.
You may also have a cracked coil housing causing the spark to jump.
