Coils - when to change?

chromebumpers · Dec 26, 2012

Do you just change the ign. coils when the test numbers are off? I'm well aware that the primary coil lead configuration is side to side terminal connections and there should be resistance of 0.75 to 0.81 ohms. Secondary, the center to side connection should be 10,000 to 11,000 oHms - what amount of deviation either way of the recommended ohm range should a coil need replacing? Secondly, Is there any benifit to replacing a standard coil with one of those "Blaster" types? (remember, we're talking about OEM distributor/points.

grumpyvette · Dec 27, 2012

If your getting a bright blue spark, with an audible snap when you pull off an ignition wire and hold it about a 1/2" from a good ground while the engines running I doubt your coils defective or needs replacing, but other components besides the coil can be a problem,
GOOD COILS TESTED WITH AN MULTI METER SET TO OHMS
normally read ,
between 0.8 ohms-to-1.3 ohms between the positive and neg electrical connections, just the calibration on your multimeter, or test clips, can change this slightly so try to be aware of this.
10,000-13,000 ohms between either of the electrical connections and the coil to distributor wire connection terminal
and off the chart between the positive and neg electrical connections and the outer case ground.
if your experiencing an ignition problem .drop back to the basics and test your battery voltage, alternator out-put, all battery connections, frame grounds, and all ignition components like ignition wire resistance in OHMS and coils, rotors , caps and firing order,and ignition timing distributor end play and bearings,advance weights and springs, and in most of the modern engines the sensors also play a huge roll in ignition precision, things like temp sensors, crank position sensors, and maf sensors , knock sensors all effect the ignition, etc. you would be amazed at how often minor parts cause major issues

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Coils - when to change?

chromebumpers

solid fixture here in the forum

grumpyvette

Administrator