Testing for spark

[dguy]

Hi folks,

 

Those who have tested for spark on their Smarts or on similar coil-on-plug engines, what tester did you use?  I have one of these but the end which connects to the spark plug is way too flexible to clip on to plugs which sit at the bottom of a well.

[Mjolinor]

It is rarely necessary to test for a spark because the diagnostics will tell you if it is not working correctly.

[Willys]

Just take the plug out and rest the electrode against a well known ground and crank engine and you should see it firing if there is a spark....or you could touch the end while cranking to be 1000% sure....just kidding....lol.
I have one of these types of testers and have never used it.....the simple way is usually the best and easiest.
Plugs are cheap and you can spend a bit more on the best quality and that is a personal choice, something I believe in. You in this case get what you pay for, this along with wires. etc.

 

[dguy]

On 2024-06-04 at 2:19 AM, Mjolinor said:

It is rarely necessary to test for a spark because the diagnostics will tell you if it is not working correctly.

 

If only it was that easy.  I'll fire up a separate thread for the problem itself.

 

On 2024-06-04 at 8:25 AM, Willys said:

Just take the plug out and rest the electrode against a well known ground and crank engine and you should see it firing if there is a spark....or you could touch the end while cranking to be 1000% sure....just kidding....lol.
I have one of these types of testers and have never used it.....the simple way is usually the best and easiest.
Plugs are cheap and you can spend a bit more on the best quality and that is a personal choice, something I believe in. You in this case get what you pay for, this along with wires. etc.

 

Been there, done that, even used the screwdriver in a plug boot technique in the past.  If the Smart's coils would snap in place over the plugs I would have tried as you describe, but instead they have a spring loaded pressure contact.  Keeping the plug's terminal in positive contact with the coil, while grounding the plug body somewhere was too fiddly for my paws.

I found a Lisle 20580 (see attached pic) which did the job.  While its rigid piece which is intended to reach the spark plug on C.O.P. engines was too long to use on the Smart without lowering the engine, the straight boot on the other wire was sufficiently firm to clip on to the plug.