14 replies to this topic

[MaryQuant88]

My car cut out on me the other day and ive traced the problem down to my coil, the thing is its only a month or so old, but it has happend to the coil before this one too about 2 months ago. Is it just a fault in this coil or are there things i should look out for incase it happens again?

[Jimmyarm]

Are you using a ballast coil in a non ballast set up or vice versa ? That is the usual reason for them going.

Check its wired in the right way round as well

A lot of the cheaper aftermarket electric bits are absolute poo and dont last two minutes so it could just be that !

[MaryQuant88]

Are you using a ballast coil in a non ballast set up or vice versa ?

A what now? Its totally standard 1988 998cc engine, and yes the Coil is wired right, must be a fault in the coil then?

[Big_Adam]

Think we need Mr Jammy, He seems very knowing on the whole ballast thingy.

[Jimmyarm]

I have the same year car, and its a balast set up.

Does it say 'balast coil' on the coil ? Or is it just a standard 12v coil ?

[MaryQuant88]

Doesnt say anything like that on it, Its just the cheapest Coil from Lucas

All its got on the Coil itself is Posative and negative symbols at the top and on the bottom 'DLB101 TESTED 08/06' part code i guess

Just been shaking it up and down, and it sounds like theres water inside!

[Jammy]

There is an oil inside, which keeps is cool. Thats why its a bad idea to stick beer or Red Bull cans around them. Do that and it stops the coil from getting rid of the heat that the coil generates!

One sec while I look up the part number.

Have a look at this article on MiniSpares. I have a feeling you have a non-ballast coil with a ballast ignition wiring.

I haven't been able to double check that the DLB101 is for a non-ballast system.

You can check whether your system is ballast-resisted or not by looking at the wires connected to your coil, if there is a pink wire (with a green tracer through it apparently) then thats the ballast resised wire, and you need a 9V coil.

[MaryQuant88]

The cables ive got going in are White and Brown(or a faded pink) with 'RESISTIV' written on it and a White & Yellow cable going to the Posative side. Ive also got a black cable going in, but that only goes from the coil to a smallthing (which i dont know what it is) but it also stuck to the coil braket.

and Black & White going to the Negative side

Does this help?

Edited by MaryQuant88, 27 November 2006 - 03:37 PM.

[Jimmyarm]

The cables ive got going in are White and Brown(or a faded pink) with 'RESISTIV' written on it and a White & Yellow cable going to the Posative side. Ive also got a black cable going in, but that only goes from the coil to a smallthing (which i dont know what it is) but it also stuck to the coil braket.

It sounds just like mine (I couldnt find a pink wire either!) which is ballasted.

If the coil doesnt say ballasted on it, then its very unlikely that it is.

Funny little story, when I changed the condensor on my mini a while back I didnt really know what I was doint so I took that little thing on the coil bracket off and thought 'this must be it, they look sort of similar' and put my new condensor there instead of where it is supposed to go !

Only when I took the lid off the dizzy did I realise my error !

[fikus01]

isnt the dlb105 the resistive coil? and the 101 a standard coil?? either way make sure you ask for a ballasted type coil or you'll either blow coils or melt points or both!!

[MaryQuant88]

or melt points

Would that explain why the plastic around the steel/alloy whatever where the spark jumps from the rotor arm inside the dizzy cap has melted a wee bit?

[fikus01]

yes

[dklawson]

???

Let's review the terminology. First, to "stabilize" something is to "make it steady". In the case of ignition systems, "ballast" is a method of trying to stabilize the voltage supplied to the coil so the spark is consistently strong... even when cranking the engine over on the starter.

Coils are not internally ballasted. They are either coils for ballast ignitions (sometimes called 6 volt coils) or they are standard coils. Beyond that you get into specialty products like HEI coils and such which are not part of this discussion. A standard coil is wound such that it provides about 3 ohms of series resistance when you measure its primary windings. There is no separate internal ballast resistor. Cut one open and you'll see (or actually... you won't see).

A ballast ignition coil is wound differently and produces a series resistance closer to about 1.5 ohms. It must be used with a ballast resistor IN SERIES with its primary connections to limit the current flowing. The combined resistance of the EXTERNAL ballast resistor and the coil will be close to 3 ohms. (All these values are nominal. Don't start flaming me when you measure your coil at 2.6 Ohms or something).

Both coil arrangements allow current flowing from the ignition switch to pass through the coil, through the points (distributor) to chassis ground. They differ in that the ballast ignition system has an additional direct wire connection to a switched terminal on the starter solenoid. Why? When you engage the starter, most the current goes towards turning the engine over and the system voltage drops. This creates a weaker spark at the plugs. The ballast ignition system provides the connection between the starter solenoid and the coil (+) terminal to bypass the ballast resistor. This allows more current to flow through the coil, and allows the coil to operate at a higher voltage so it develops a hotter spark WHILE CRANKING. As soon as the starter solenoid drops out, the normal current flow is restored and power to the coil comes from the ignition switch through the ballast resistor.

IF you use a ballast ignition coil WITHOUT a ballast resistor, you will let too much current pass through it and the points in the dizzy will quickly burn up. You must use the ballast resistor with low resistance coils. You said your car has the pinkish wire feeding coil (+). That IS your ballast resistor so you need a ballast coil.

IF you use a standard coil on a car with a ballast resistor, the series resistance is too high. (1.5 Ohms from the ballast resistor + 3 Ohms for the coil = 4.5 Ohms). This significantly reduces the current flowing and the operating voltage of the coil. In effect, you're quenching the spark... making it weak. You won't damage the coil but you'll just find the car VERY hard to start and may have running problems.

The poles inside the dizzy cap and the end of the rotor will burn/pit over time. This is normal. As part of any regular tune up I scrape off any build up using the tip of a screwdriver. Don't put sandpaper or any abrasive inside the cap to clean the poles as you don't want to risk making score lines on the insulating material. Score marks either on the outside or inside of the cap can allow a current path along the surface of the cap which will result in misfires.

[Jimmyarm]

:clap:

edit; oh why dont we have that smiley !

Edited by Jimmyarm, 28 November 2006 - 02:34 PM.

[fikus01]

apologies for the bad terminology, was just explaining it in basic terms!! for those who dont understand it i've found it hard to explain the ballasted system!! just easier to say "part" is wrong do this!!

admittdly it doesnt teach them but there are folk out there like urself that are available for that!!