Hello!
My T-bird had a barrel type (oil cooled like for Duraspark) ignition coil installed by the previous owner. It was OK, but the factory socket wasn't holding well on it, so I decided to go back to orginal setup.
The barral type coil had ground wire connected directly from the factory socket, while (+) had additional capacitor connected between factory socket contact and plug in the coil.
So I got a NOS Motorcraft TFI coil on eBay, and factory bracked from "fordnut" (thanks again Joe) and installed everything, so it looks factory now. Engine started right up and it seems to start up faster than before. But when I turned off the radio and blower I heard some kind of ticking noise like the one you could hear in some car radios with poits distributor system. Where's the sound comming from... I dunno. Is it possible that it's a sound of the new coil traveling thru the subframe and gets audible thry the firewall? The sound is of course increasing it's frequency with engine rpm increase.
What it may be? Is there something missing in my T-bird? What was that capacitor on the (+) wire going to the barrel type coil for?
I was fixing up the 1994 Town Car lately and it had some small barrel next to each coil. Are they for some electricity noise reduction?
Thanks in advance for any ideas!
Mariusz...
Are you sure it is a capacitor? Older ignition systems, like Duraspark, used a current limiting resister in series with the coil.
Look under the hood when it is dark and see if it is arcing anywhere.
The resistor is usually ceramic. The metal "barrel" thing is a capacitor, or condenser, and it's there to absorb electrical spikes which can cause radio noise and damage the ignition module (and in the old days, could cause points to wear out prematurely). That's likely your problem, Shevretti...
If a capacitor goes from + to ground it could be a noise suppressor.
If the + has to go through a capacitor to get to the coil it would not work at all.
Where should I have the noise suppressor connected to the factory wiring? I can't find any "homless" wire there.
Here are some pics of how the old and new setup looks. Maybe you will notice something wrong?
(http://www.thunderbird.org.pl/mario/old_coil-1.JPG)
(http://www.thunderbird.org.pl/mario/old_coil-2.JPG)
(http://www.thunderbird.org.pl/mario/new_coil-1.JPG)
(http://www.thunderbird.org.pl/mario/new_coil-2.JPG)
P.S. If somebody could take a few pics of their factory coil and wires around it and send it to my e-mail address I'd be very thankfull :)
That does look like an electrical noise suppression capacitor. the ground connection is the tab with the hole in it.
I do not think the stock TFI ignition uses one. You do not have noise on your radio, so I do not think the capacitor is the answer to your problem.
That coil mounting must have a good connection to ground. Does it have a star washer to cut through the paint?
what he said,,,,,,,,,,all of it.
now remove that paint on the coil bracket (each side).
You want that bolt to make perfect contact with the bracked so when it passes thru the strut tower, your coil is grounded good.
If you like "AM" band stations, your screwed,,,,, even with the noise filter, you arent gonna get rid of that noise.
My 1990 bronco has the round cap mounted to the coil bracket,, its ironic that its also a TFI system but my coug does not have this setup. The coug nor any other coug or tbird i know of with TFI has the CAP/Filter,,,,,,,,, only the truck models do.
one of the many jobs of a capacitor(since its nothing more than a battery holding a temporary charge) is to pass DC while blocking AC (generated by various things in your car due to feedback),,,,,,,,sending this AC potential straight to ground.
I have two factory screws with star washers on them. I think they should ground the coil pretty well, but it's not a bad idea to remove the paint from the bracket anyway.
I was just wondering if somebody on our forum may have those factory screws holding the bracket to the strut tower and would like to get rid of them for a few bucks? I'd buy two or three of them as I have some odd screws holding the coils in my other Fords too (one in the T-bird is missing).
After doing some research I noticed that the strange sound is comming directly from the coil! It's a buzzing sound like from transformer station. I could hear it only using stethoscope and found it travels thru the strut tower and to the firewall. I'll check for bad ground, but I've already ordered a new coil for my T-bird, just in case.