tracyballard

Before I blow a lot of money on new coils to try to cure my misfire on 5 which is no longer giving codes, but still missing, I thought perhaps I should actually see if they are in bad shape first. Can you perform a diagnostic test on the cop with a multimeter? Such as testing the resistance across the primary and secondary circuits? what should the readings be if so?? thanks!

johncrist1988

Yes, you can. And just like that, too. Measure resistance and measure current. Ground out on the chassis.

robb15033

I have Ohm'ed them out on a bad set & got consistent Ohm readings phase to phase all the way around. Tricky for me.

tracyballard

thanks for the answer. Do you happen to know what setting I should use on the ohm meter, and what the reading should be?

johncrist1988

My multimeter auto ranges. When I touch the primary terminals (the ones on the inside) I get a resistance of 0.500 ohms. When I touch the secondary terminals I get 5,520 ohms.

tracyballard

I guess since I'm using a 20 year old multi meter I may be at a disadvantage. but I'll see if I can get readings similar to the ones you've listed. those are about the same as some specs I saw for an older Ford coil pack, so I guess nothing changes much. thanks for the input!!

MagnumRooster

So how exactly does a person accomplish this, the current readings that is, with everything unhooked to gain access to the COP's? What kind of current is supposed to be flowing thru these things, I know they are supposed to put out somewhere in the kV area for voltage but usually high voltage means low current.
I guess my biggest question is are you supposed to unhook one, crank the motor take the reading then proceed to do the same all the way around the motor?
Another question, how can you know what exact cylinder is misfiring?
I am having issues with bucking on acceleration in lower rpm's that i feel might be related to some emissions type issue. But i would like to rule out COP.