Simple ignition Leads Question

[squidda]

If you check an ignition lead for resistance and it tests OK, can it still be faulty?

Was going to change leads on my ecotec, Currently has eagles that are at least 6 years old. a mate said to just check them for resistance and if they check out Ok, don't bother.

Also what leads to recommend or stay away from. can get Bosch for supercheap for about $50.
thanks

 

[ssute57l]

If you have not changed them in 6 yrs, your probably better of changing them anyway, as they may fail at anytime in the future and to ensure you have healthy spark, having said that, they may go for yrs.

Go with what you got or get the bosch leads, price genuine if you like.

 

[yobbo88]

why after i change spark leads on my 6 cyl vh, with spark plugs that were god knows how old, would the car start misfiring and have problems starting (probably 50% of the time) from as far as im aware new decent leads? they are in correct order etc etc been over it 1000 times... 2 new sets of leads and the problems still there.... the car was completely fine before but thought it would be a good idea to change them, acceleration is rough at the start then smoothes out, i thought it might me dizzy/points but the problem started straight after the lead changes... i dunno. sorry for big post but its better than starting a new thread

 

[jules]

check the plugs on the end of the leads, that they haven't been bent when you put them on and aren't burnt. they need to make good contact at both ends. some leads seem to have funny shaped contacts that could be the problem, that's just my impression tho..

 

[HATER VP]

The coil and dizzy cap are probley fuked. If the leads are starting to fail, the cap needs to work twice as hard to provide spark. The the coil does the same.

 

[shaggerz]

Leads can indeed be faulty even if they test ok resistance-wise. There can be breakout if the insulation has deteriorated on the lead. This is NOT visible but occurs when the high voltage pulse through the lead finds a better path to ground (i.e. the spark jumps through the insulation to a grounded point such as the engine rather than across the spark gap on the plug).

25 000 volts can break through insulation and travel quite a distance on its own. Ever started a car with one of the leads off? Its quite pretty watching those 2 inch long arcs jump all over the engine bay.