Thread: Faulty Spark Plug Lead

Are you sure its the leads and not the plugs? I had similar problems in the past, pulled the plugs out and looked fine. I bought a new set anyway and that made it run smoother. So maybe a set of plugs is the go, its a cheapish replacement.

Hi Stooge,

I replaced the plugs last time it played up, so about 4 months ago. Did not make a difference. Any way of checking plugs? Its hard when it does not happen all the time

Google is your friend. Have a read of this. Lead resitance gets a mention down the page a bit.

http://www.mr2.com/TEXT/DavidKucharczyk/ignition.html

ohms meter on the lead will give you the answer to your leads condition, but you will have to work out wether they are the resistance type or not first. They should all be identical in resistance regardless of length.

dont forget to wiggle them while you do it.

plugs are about the same.

Originally Posted by Blknight.aus

ohms meter on the lead will give you the answer to your leads condition, but you will have to work out wether they are the resistance type or not first. They should all be identical in resistance regardless of length.

dont forget to wiggle them while you do it.

plugs are about the same.

Yes - I posted something about a lead problem, probably about a year ago. Measure the resistance of each lead with an ohm meter - should all be about the same. The faulty one I had had visible burning in the centre conductor from one end, that you could see by looking in the end. Can't remember which end it was. With one faulty, I replaced the lot, as they were all the same age.

John

Thanks all. I just took a stab and ran the multimeter over them using ohm and one was higher then the others, most read about 6-7, one read 12. I also started the car and with a dark night i could see blue sparks within the wire..... more if i held the lead or the lead was against something. I think it is time for a whole set of leads.

Originally Posted by stikman

Thanks all. I just took a stab and ran the multimeter over them using ohm and one was higher then the others, most read about 6-7, one read 12. I also started the car and with a dark night i could see blue sparks within the wire..... more if i held the lead or the lead was against something. I think it is time for a whole set of leads.

Sounds like you do have one faulty, and yes, replace the lot!

John

Originally Posted by stikman

I also started the car and with a dark night i could see blue sparks within the wire..... more if i held the lead or the lead was against something.

I was just going to suggest this as a simple diagnostic technique for dodgy leads.

Seems you've found the culprit!