1987 Ranger Ignition Coil Test Results on a 2.9

[greaseyfingers]

The ohm resistance between the small side terminals of the coil was .6 ohms.

The resistance between on either side terminal and the center high output terminal was 8,100 ohms.

Are these test results out of range, that could be causing malfunctioning ignition issues?

 

[kunar]

i don't have any idea if these results are within proper range or not, but i will tell you that when my coil failed it tested good according to the book.... take it for what it's worth.

 

[greaseyfingers]

i don't have any idea if these results are within proper range or not, but i will tell you that when my coil failed it tested good according to the book.... take it for what it's worth.

How was your ignition coil affecting the idling and driving performance of your engine, before your replaced your failed coil?

Did your car's engine have any of these symptoms, like hesitation while starting the car, or weak throttle response during acceleration, or rough idle, or misfiring, or backfiring, and dim or weak accessories like the headlights and radio.

 

[tec2484]

All of that can be caused by bad grounds.

 

[adsm08]

I'd check timing and battery voltage with the engine running. That sounds more like a TFI or alternator/charging system issue to me.


Your secondary ignition resistance is a bit high, it's supposed to be closer to 6000 ohm, but it should still be functional.

 

[kunar]

yeah, that doesnt sound like a coil issue.... that sounds like a battery charging or ground issue. when my coil went bad, the engine just quit. new coil fixed it though.

 

[greaseyfingers]

yeah, that doesnt sound like a coil issue.... that sounds like a battery charging or ground issue. when my coil went bad, the engine just quit. new coil fixed it though.

I read on several websites that stated the following about ignition coils>

If the ignition coil is going bad, but is still marginally functional, it will
provide electrical current for some of the plugs, but not all. This problem
may be mistaken as a bad spark plug. If the weak coil can not maintain
a spark for all the plugs, the vehicle will run poorly and may buck, feel
sluggish, fail to accelerate properly, run loudly and shake.
http://www.ehow.com/list_6426093_signs-bad-ignition-coil.html

6 Symtoms if Ignition Coil Failure
If your vehicle is behaving in an eccentric fashion and you have problems with it running smoothly, it could be showing signs of ignition coil failure. When you start your vehicle, the ignition coil takes power from the battery and relays it to the spark plugs.
www.doityourself.com/stry/6-symptoms-of-ignition-coil-failure

If you have a complete coil failure, it would be easy to tell as your car
won't start. If you have the more common corrosion problem, then it all
comes down to a weaker and intermittent spark as the transmission of your
electrical current will be disrupted. Symptoms of this problem include
hesitation while starting the car, weak throttle response during
acceleration, rough idle, misfiring, backfiring, and dim or weak accessories
like the headlights and radio.
http://www.redlinemotive.com/replacement/ford/ignitioncoil.asp

 

[kimcrwbr1]

Take all your grounds apart and sand them metal to metal every one if the ground from the battery to the engine is corroded at the batt terminal replace it then check you charging system. You need to assure your voltage to the coil is good before you can really test the coil using a spark tester but a quick check would be to put a plug in the coil wire to the dizzy and have someone crank on it you should have a brite blue crisp spark. Get the wires and charging system up to snuff first fully charge the battery then test the system.

 

[kimcrwbr1]

Same with the pos battery terminal.

 

[adsm08]

I read on several websites that stated the following about ignition coils....

That's great. Now what do you (or they) know about the specific functioning and failure of the 2.9's TFI system?


The coils do go bad, yes. It is FAR FAR FAR more common for the TFI module to fail. They are the weak point of the system, and since the coil can't fire right without the TFI doing it's job right, it will cause the same symptoms.


The thing that you just posted there sounds like it was written about a waste-spark coil pack system like what is found on the 4.0.

 

[kunar]

The thing that you just posted there sounds like it was written about a waste-spark coil pack system like what is found on the 4.0.

thats what i was thinking... coil packs, not coil and distributor....

 

[disciplerocks]

waste-spark coil pack

Lol

 

[adsm08]

Lol

?

 

[disciplerocks]

Never heard Fords shared spark called that.