What are the symptoms of IGNITION COIL failure?

[Chrome_GT]

Hey all, got ongoing issues with the Capri:
*Spark is there but i'm suspecting it is weeker than it should be
*points are pitting regularly - far more often than they used too years ago. Note that replacing condensors didn't fix this. I always replace condensors when i replace points and set points using dwell meter not just feeler gauges.
*Have had issues starting and has died while running on moist days

Does this sound like it could be the snowballing effect of having a bung coil?

What are the typical symptoms of coil failure?

What diagnostic checks are there?

[Mark_H.]

Hi,
Not done this check myself but the coil is designed to run under normal condition with a 7 volt supply to the low tension terminal. This voltage is increased to approx. 31000volts by the coil windings working in conjunction with the distributor contact breaker points.
The coil has 3 terminals 2 low tension and 1 high tension terminal.
The positive LT lead supplies the power source to the coil from the battery via the ignition switch.
The negative LT lead connects the coil to the distributor.
The main HT lead supplies the high voltage, created within the coil, to the spark plugs via the distributor cap.
Hope this helps.
Mark H.

For the V6 engines the coil is a twin pack oil filled, still looks like an ordinary coil but 1 half can break down and the car then runs on 4 cylinders and is as lumpy as hell.

[Dave]

Sounds like it could be coil to me.
It really is very worthwhile changing to electronic ignition, and there are lots of choices and price ranges in the ways you can do it.

[Wardy257]

If you want to go electronic just rob it off a Sierra with the same engine. The earlier the Sierra the simpler it will be.

[Chrome_GT]

Just realised i hadn't updated this. Turns out i was running the wrong coil type. I had a non ballast coil even though my capri does have a ballast resistor. My understanding is that this reduces the voltage to the ignition considerably. Problems disappeared when i swapped it.
Cheers
Ray

[Matty28i]

Just been talking about the "Coil Robbing Issue" this afternoon.

A bad earth from the engine to bodywork, it would cause the starter motor to draw all the current and yet you could bump start a car in a few feet.

Worth checking the engine earths.

Matty

[rappy]

Hi all sorry to hi jack post had some issued car was running fine then left it sat on drive way and it died. After a few mins started again so put it in garage and died again so connected strobe light up foind its dropping spark. Previously fitted new points.condenser.cap rotor plugs amd.leads. coil is a year old but.not gteatest make. Car is a 83 1690 Ls converted to 2000 pinto

Going.nuts thinking.possibly coil fault any other pointers

Cheers

[rappy]

1600 not 1690

[Peter-S]

I'd try a different condenser first - do you still have the old one? - they are notorious for failing even when fairly new.

[Paul G]

Hi all sorry to hi jack post had some issued car was running fine then left it sat on drive way and it died. After a few mins started again so put it in garage and died again so connected strobe light up foind its dropping spark. Previously fitted new points.condenser.cap rotor plugs amd.leads. coil is a year old but.not gteatest make. Car is a 83 1690 Ls converted to 2000 pinto

Going.nuts thinking.possibly coil fault any other pointers

Cheers

Start with the basics - is the coil clamp securely tightened and the screws tight in the inner wing? Are all other earths ok, ie engine block, small earth wire from rear of inlet manifold to bulkhead and the battery terminals clean and tight?

The replacement coil you fitted - is it definitely a ballast coil assuming you're still using the original wiring.

Another thing to look at is the condenser. There are some absolute crappy ones about these days that don't last 5 minutes and that could be a cause of the problems. It may overheat after the engine has been running a while and cause the breakdown.