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What do you think about replacing the coil on a truck with 90,000 miles. Seems to me that the original can't be as good as new after all that. Truck runs great, but seems to take a bit longer to start up than it should. Battery is good, recently tuned up and new plug wires, etc. I am not looking for some super coil, just a Motorcraft replacement.
INLINE SIX POWER!
300 Cubic Inches of Low RPM Truck Torque! And twin-I-beams too!
"Drive a stick young man! There'll be time for automatics when you're old and unable."
Hi TallPaul, well for peace of mind and cost, replacing the coil is no big deal for sure. And if you do, make sure that the wires and cap are all good too.
If I do it, it probably will be the Standard and certainly won't be the Wells. I asked the guy at Autozone why the dealer would be four times higher, noting it couldn't all be markup. The guy said he didn't know, but that maybe the dealer has a "more better" part.
Whoops. Not the name of the place. Can't remember, but it is one of those traditional auto parts stores like from before the times of discount chain auto parts stores.
What about NOS? Sitting on a shelf shouldn't hurt these things, should it? It's just an autotransformer soaking in oil after all.
Near as I can tell, my 64 went through one of the 15 dollar specials in about 12,000 miles. I shoulda known better. They can get intermittent when hot (a gazillion turns of very fine wire in the secondary HT) which means they work long enough to get you stranded somewhere.
I like to mount the coil on the inner fender away from engine heat. Maybe this is why I never had any coil failures. I have an old Sun coil tester sitting on a shelf. Think it was designed to heat up the coil and check output with a set of motor driven points.
I recommend replacing it with a good quality one from a part store, even if it isn't bad. I just did one on my 391 F-600. The old one was cracked and had a resistence of 2.4 megs ohms on the coil tower to the + side. Needless to say it didn't start up till it was replaced! The correct resistence reading on a basic coil is 1 to 2 ohms on the measurement between the + positive and - negative terminals.
While the reading between either of those two and the tower to cap wire plugin, resistence should read about 2 to 4 ohms maybe 6 ohms if there is an internal resister built into it. If there is a higher reading (or an open-no reading), you will get an attenuated spark or less than the 25-30,000 volts you need to have efficient combustion for a typical standard compression engine.
Keepem rollin!
Rob: 1969 F-600 391, 4-SPD, pto/hydrolic, Dualies, flatbed, old farm truck land barge
Thanks, Guess the first thing I should do is get my ohm meter out and see what is going on with the original coil. If I need one, the Standard sounds like a good bet, thought the blaster is about the same $$$ for me.
And does anybody know what NOS really means? I know it stands for nitrous (brand name?) but also has something to do (I think) with standard or original equipment parts or something like that?
>And does anybody know what NOS really means? I know it
>stands for nitrous (brand name?) but also has something to
>do (I think) with standard or original equipment parts or
>something like that?