checking coil packs without multi meter

[macka75]

hi all

i was scanning through the forums reading about testing coil packs as mine is suspicious and i dont own a multi meter.
came across one that explained how to do it with out one.

turn car off take leads off coil packs ( working one at coil pack at a time), start car up and check spark is jumping between posts, if it jumps anywhere else the coil is stuffed it read.

tried this on mine and the spark on the middle coil pack was jumping to the pack and not between the posts.

going to get coil pack from wreckers to swap it over tomorrow. if this works it is a simple way to test them without the right tools. hope this helps a few out there

 

[hako]

That test doesn't sound right to me - you should be connecting the 2 leads from the one coil to 2 sparkplugs with very large spark gaps. Make sure the plugs are earthed.
The way you describe can destroy the coil as the high voltage finds the shortest path to earth and in doing so can burn a hole thru the coil windings.
As described, the spark cannot jump between the 2 posts as they are the same potential...they are connected to each other. Pretty sure what I've said is correct...but I ain't always right...
Good Luck.

 

[macka75]

on the first and last coil packs the spark jumped between posts. ( visable constant spark between posts)

 

[v6lux]

The way you describe can destroy the coil as the high voltage finds the shortest path to earth and in doing so can burn a hole thru the coil windings

Yep!

A quick way to waste money is to destroy your good coil packs with this method. I'm sure licensed mechanics will promote this method when a DIY Pro named macka75 asks that same question!

You can get a Multi Meter for $5.

 

[macka75]

Yep!

A quick way to waste money is to destroy your good coil packs with this method. I'm sure licensed mechanics will promote this method when a DIY Pro named macka75 asks that same question!

You can get a Multi Meter for $5.

if u read the post i started saying i found it going through forums, it is NOT something i just came up with. i cant get to a multi meter as my car is not running right and i dont want to risk driving it.
here is the post i read.
http://forums.justcommodores.com.au/vt-vx-holden-commodore-1997-2002/93038-my-coil-pack-stuffed.html
" DIY pro" i have never claimed to be
i have spent many years around cars but have always had older holdens and a vq v8 caprice, so im still learning about coil packs and alot other things assosiated with newer cars, thats why i ask on this forum.

 

[turbo45]

hi you will need to get an old spark plug and tack weld a alligator clip to upper threaded section of plug(hex section) then remove the earth electrode from the plug, so the spark has to jump across to side of plug,,this will not damage coils. Now the old spark plug is converted into spark tester. Now hook the tester between lead and coil post. eg alligator clip on coil post and lead onto top of tester. Run the engine and check to see if spark is jumping across ok,,Be careful not to touch as you will get nasty shock,, Also if engine missfires while doing this,it means coil pack or leads faulty on that section. Could also mean module under the coils is faulty also... If you find that spark is not jumping across, swap coils to see if problem tranfers to other cyls. this will only work if you have three seperate coils. This is confusing i know.

 

[v6lux]

" DIY pro"

Sorry dude, you prolly are good at DIY and the remark was actually intended to be aimed at "Jo-Blow" (which I should have typed instead) to deter others from using that method.

Anyway, I had a faulty coil pack and the engine was running smooth-as at all revs including free and under load. Problem was I was getting occasional backfires.

I have not tried turbo45's method, so can't dispute it, but I believe the meter is the ultimate method. The faulty coil was easily found and replaced.

 

[Brett_jjj]

Ive seen these coils show up ok on a multimeter but still cause a misfire.The best way is to get a spare coil to use for testing purposes if your engine is running bad or has a miss etc.It took me ages to find what was causing a miss after testing the coils on a multimeter and they showed they were fine,but it ended up that one coil was stuffed anyway.

 

[macka75]

the problem coil was found. the test i used did work but i guess im lucky not to have stuffed the other coils. but it did show me the problem coil.
so much knowledge can be learnt from this forum, and i am slowly learning the wrongs from rights.
thanks for the help over the past few weeks all.

the spark plug tester sounds like a great idea.

 

[acarmody]

I don't think its been mentioned, and I know its obvious but I'm going to point it out anyway. If testing the coils by disconnecting (instead of using test coil), make sure you disable the injectors on those cylinders. Safety first.