12 replies to this topic

[longbridge4life]

Hi everyone, calling all coil boffins
Iv'e had starting issues lately which is sorted but have rough idle and bogging when accelerator pressed anyhooo,

I took these reading on my coil yesterday and read in another post that a Ballasted coil with no leads connected should read 1.5Ohms
I have a ballasted coil fitted but with wires disconnected it reads 3.1Ohms ?? does this mean its a non ballast coil? yet it has a sticker on it saying it is.
Can you throw any light on the matter and what effects it may have if it's wrong
Cheers

A+ engine
Lumenition magnetronic Ignition module
Intermotor 11070 ballast ignition coil

Ignition switched on reading are:
Battery 12.48V
coil + to - wires connected 4.7V
supply to + on lumenition module 11.5V
coil with no wires attached 3.1 Ohms

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•  coil connections at present.jpg   72.08K   16 downloads

Edited by longbridge4life, 29 June 2012 - 10:51 AM.

[lrostoke]

You have your lumination connected to the coil in that picture ?? at least it looks like that...

[longbridge4life]

Ooooops wrong piccy that's how it used to be till i supplied a 12v feed from the fuse box......updated the piccy now to what it is :)

[Ethel]

It does sound like it's a non ballasted coil.

[dklawson]

The terms "ballast" and "ballasted" are often misapplied or poorly used by manufacturers. A "standard" coil will nominally be about 3 Ohms. Sometimes manufacturers refer to those coils as "internally ballasted". That is very misleading as it implies you would use that coil on a ballast ignition system and that is not true.

You have the pink and yellow wires and they are on coil (+). Those are the wires used with ballast ignition systems. The voltage measurements are complicated by the fact that you have an electronic ignition. Please perform one more test and report your findings.

Start with all the wires attached to the coil.
Place a temporary jumper wire from coil (-) to earth (a head bolt/stud or similar).
Switch on the ignition and measure the voltage from coil (+) to earth.
If you find coil (+) at 6V to 9V, you have a ballast power supply for the coil and you need a ballast coil (which will measure between 1-2 Ohms).
If you find coil (+) at 12V, you have a standard ignition system and you need a standard coil that will measure about 3 Ohms.

Please let us know what you find when you make the measurement suggested above.

[longbridge4life]

Roger that captain,I'll be back and thanks for your reply, I want to get the ignition purring :)

[Ethel]

If it turns out to be a "full fat" coil, you could just hook up that 12v to the coil as well as the electronic ignition.

[bmcecosse]

A ballast coil will be 1.5 / 2 ohms - your 3 ohm coil is for straight 12 volt application.

[longbridge4life]

Right I've had a bash. Take a look at these pictures and see if it's alright. Note when i put my tester connections together in one pic it does not read zero thought I'd point that out. I put a temporary cable from the coil negative to the cylinder head bolt.

First pic is 5.7V with temporary lead
second pic is with all wires disconnected etc HT lead and reading Ohms at the 200 scale....is that the right scale to use? hmmm seems too high think i messed that one up.

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Edited by longbridge4life, 29 June 2012 - 01:29 PM.

[dklawson]

I cannot comment on the ohm readings you took except to say that with no wires connected to the coil you would expect the reading to match what you reported earlier. Your probe-to-probe resistance reading is alarmingly high. I have never seen a meter/probes that read higher than (1) ohm when its leads are held together. Try a new battery in the meter and be sure the probe tips and plugs are spotlessly clean.

Assuming you trust your meter, the voltage measurement you took of just under 6V confirms the coil wiring is for a ballast coil. As Ethel said... if you are certain the coil you bought really measures 3 Ohms, the quickest fix for you is to run a wire from coil (+) to the same terminal where you are getting power for the Lumenition red wire.

[longbridge4life]

Hehe I changed the battery in my multipoint tester today and i got a reading from my coil of 1.5 Ohm! just goes to show you how a dodgy battery in a tester can throw you. I'll run it on this coil for now and see if it still does the job.

I bought an old lucas coil off the carboot today for £2 it's a 11P12 45334A with a reading of 3.2 Ohm. I may wire this in the future for a full 12v set up. What do you guys reckon stick with ballast on an electronic unit or go "Full fat"??

Thanks again for all your help

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Edited by longbridge4life, 02 July 2012 - 06:53 PM.

[dklawson]

Which you choose to use depends on who you ask.

The ballast setup does make it easier for an engine to start, particularly in winter. However, the pink wire has a bad reputation for overheating and damaging the loom. Many people consider that reason enough to do away with the ballast ignition and run the standard coil. I usually advise keeping the ballast coil but replacing the pink wire with an external ballast resistor. That is the setup many other car makers chose.

In your case, you now own both coils so you could go either way. It is not like you would have to buy another new expensive coil to change.

[longbridge4life]

Thanks very much for your advice it's been much appriciated the last few weeks :)