new coils, oh my what power
06-23-2009, 01:14 PM
#20
06-23-2009, 02:30 PM
#21
Rennlist Member
Logic tells me that "if it ain't broke don't fix it". My car runs good, gets good gas mileage, pulls stong(-er than my other C4). But, I am tempted to do this bit of "maintenance" It's only another $100, right?
I do note that when I unplug each igniter at idle, the engine rpm drops and stumbles a bit - on either coil. I would not have expected to see this. (I don't recall that my other C4 exhibited this drop/stumble).
I do note that when I unplug each igniter at idle, the engine rpm drops and stumbles a bit - on either coil. I would not have expected to see this. (I don't recall that my other C4 exhibited this drop/stumble).
06-23-2009, 03:19 PM
#22
Three Wheelin'
Logic tells me that "if it ain't broke don't fix it". My car runs good, gets good gas mileage, pulls stong(-er than my other C4). But, I am tempted to do this bit of "maintenance" It's only another $100, right?
I do note that when I unplug each igniter at idle, the engine rpm drops and stumbles a bit - on either coil. I would not have expected to see this. (I don't recall that my other C4 exhibited this drop/stumble).
I do note that when I unplug each igniter at idle, the engine rpm drops and stumbles a bit - on either coil. I would not have expected to see this. (I don't recall that my other C4 exhibited this drop/stumble).
Just kidding. I am going to put a set in when I get back from vacation. As well as rebuilding the pedal cluster, resetting the ride height, redoing the alingment, resealing the power housing I screwed up, etc. I consider it therapy.
06-23-2009, 05:18 PM
#23
Professor of Pending Projects
Rennlist Member
Rennlist Member
Logic tells me that "if it ain't broke don't fix it". My car runs good, gets good gas mileage, pulls stong(-er than my other C4). But, I am tempted to do this bit of "maintenance" It's only another $100, right?
I do note that when I unplug each igniter at idle, the engine rpm drops and stumbles a bit - on either coil. I would not have expected to see this. (I don't recall that my other C4 exhibited this drop/stumble).
I do note that when I unplug each igniter at idle, the engine rpm drops and stumbles a bit - on either coil. I would not have expected to see this. (I don't recall that my other C4 exhibited this drop/stumble).
06-23-2009, 11:54 PM
#25
Racer
Join Date: Feb 2004
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I am interested but I would love to understand why or how new coils produce more power than older ones. I just thought until now that if they worked, they worked.
Thanks
Peter
Thanks
Peter
06-24-2009, 05:34 AM
#27
Three Wheelin'
Join Date: Dec 2003
Location: Rancho Palos Verdes CA
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Does their voltage rating fall off over time?
I guess that is why there is so much aftermarket ignition stuff out there. Hotter spark more power.
Looks like another 100 bucks gone out of my wallet, good grief.
I guess that is why there is so much aftermarket ignition stuff out there. Hotter spark more power.
Looks like another 100 bucks gone out of my wallet, good grief.
06-24-2009, 06:29 AM
#28
Racer
Join Date: Jun 2008
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Typically, from the secondary of an ignition coil you'll get short pulses of about 20000 Volts - (though at a low current).
Voltages this high are hard to contain in a confined space and "leak" out with very little provocation. This is why touching an HT lead can result in belt when the engine is running even though the lead is insulated.
With this design, the insulation in the coil itself has to be as near to perfectly insulated as possible. Normally, the coil is wound with very fine wire that uses varnish as its insulation. Insulation breakdown of the varnish is a pretty rare event - it's slightly better quality than the average tin of Dulux - but it isn't unknown.
What happens is that a tiny hole appears in the varnish and the electricity "leaks" out, as a spark between the windings. This in turn punches more holes in the insulation of the destination of the spark leading to more "leaking" gradually resulting a severe deterioration of the coil's performance.
This leakage is only evident when the coil is producing a spark and will not show up using a standard resistance test with a multimeter. You could see these leaks as "spikes" on an oscilloscope and they will be propogated (at a much lower level) as electrical "noise" throughout the whole wiring loom. These spikes can cause havoc with the low voltage electronics (Christmas Tree effect?) in the car so for $100 if you haven't ever changed them in almost 20 years it may be worth a punt imo.
Voltages this high are hard to contain in a confined space and "leak" out with very little provocation. This is why touching an HT lead can result in belt when the engine is running even though the lead is insulated.
With this design, the insulation in the coil itself has to be as near to perfectly insulated as possible. Normally, the coil is wound with very fine wire that uses varnish as its insulation. Insulation breakdown of the varnish is a pretty rare event - it's slightly better quality than the average tin of Dulux - but it isn't unknown.
What happens is that a tiny hole appears in the varnish and the electricity "leaks" out, as a spark between the windings. This in turn punches more holes in the insulation of the destination of the spark leading to more "leaking" gradually resulting a severe deterioration of the coil's performance.
This leakage is only evident when the coil is producing a spark and will not show up using a standard resistance test with a multimeter. You could see these leaks as "spikes" on an oscilloscope and they will be propogated (at a much lower level) as electrical "noise" throughout the whole wiring loom. These spikes can cause havoc with the low voltage electronics (Christmas Tree effect?) in the car so for $100 if you haven't ever changed them in almost 20 years it may be worth a punt imo.
06-24-2009, 09:21 AM
#29
well, I'm going to swap mine out. the car has fits of hesitation, and then runs fine 99% of the time. They are 17 years old; can't hurt anything more than the pocketbook.
Here's another source. anyone got a preference between Autohaus and Drivewire?
Drivewire ignition coils
Here's another source. anyone got a preference between Autohaus and Drivewire?
Drivewire ignition coils
06-24-2009, 01:08 PM
#30
hmmmm
So I called auto part warehouse and spoke to a guy there. He hung up on me when I said I didn't know if I wanted to order the coils or not; just click- mid sentence even. WTF!!!!
so I called autohaus of Arizona and ordered from them.
so I called autohaus of Arizona and ordered from them.