Hi guys,

Could someone please help me with 'Coil testing procedure' for my Jag 2001 X-Type 2.5...

It's running rough at the moment and I have a feeling that it could be a faulty
coil...I have the coils out at the moment but I'm stuck because not sure on how to check/test them.


Thanks in advance guys!

 

Unfortunately there are only two ways to truly "test" your ignition coils. One is by substitution with a known good coil, the other requires an oscilloscope with an inductive current probe to test them by current draw waveform. These coils have an on-board ignition module that isolates the coil so you can't directly test it electrically.

Good luck!

 

While I am most certainly not sure of the "proper" techniques for testing the coil packs (methinks our forum friend "Thermo" will be most qualified to weigh in on this), I can safely suggest an initial test or two:

Get a hold of a V.O.M. (Volt/Ohm Meter), set it to any (or all) of the various Ohm scales, and test betwixt the differing leads, posts, plug connectors, etc.

(Number the coils, and record the results)

What I would look for initially is any serious discrepancy between reading of like posts between different coil packs. If the meter needle (or readout) jumps on one but not the other coil packs - or vice versa - you probably have a prime suspect. Or if the read-out is very different on a coil pack compared to the others.

If all appear to read closely the same (whatever readings you are getting) I would repeat the process, but would gently WHACK each coil pack with the rubber-handled end of a medium screwdriver while testing, and see if a "fault" is found that way.

Heat and vibration are the killers of the coil packs, so the "Whack Test" is actually legitimate. Heating them up with a hair dryer would also be a legitimate secondary test if they all test the same to start with, as would freezing them.

(Car parts on the kitchen table over the Holidays always always adds a certain "ambiance", too - thinks me)

Now, before anyone mentions that this is the third post in a row wherein I suggest "hit it with a hammer", please know the "Whack Test" is the single most definitive test for a bad MAF (Mass Airflow Sensor). Whack the unit: if the engine stumbles, the unit is bad.

(and as for Disgauy's having taken the whole front of his car off over that AC Clutch problem, I just think he needed a bigger hammer to whack it with to start with!)

Good Luck, let us know how it works, and yes: my Christmas Tree is a Shade Tree!



(Or as XJRguy said...)

 

Hello Steve,
Couple of questions for myself and others following this ignition coil thread:

1. Is ignition coiloutput waveform available on the IDS oscilloscope-like function?
2. Does IDS provide any output to help (other than procedure) diagnose a faulty ignition coil?
3. I have an oscilloscope and may be able to access an inductive probe.
Would you please post some information about setting up for the test and describe the waveform(s)? A bulletin, if one exists, would be much appreciated by those of us following this thread.

Disclaimer: I am not a TECH. Just a wannabe, handyguy.

Best regards,
Bill

 

Bill,

Here's something that explains it way better than I can on a keyboard.


Covers the hookup and he explains everything he is doing and why. Lot's to digest.


Cheers,

 

This is what the coil looks like, does anyone know how to test the Primary & Secondary resistances? (The connector plug has four pins) Cheers~!

 

Please refer back to post #2.

Cheers,

 

Thanks for the video Steve. That ScannerDanner is a super instructor!
A great resource.

 

That's for sure! I wish I'd found him years ago. I thought I was conscientious, but he makes me look like a slacker!

Glad you found it helpful.

Merry Christmas!