Ignition coil recommendations for MK1 Ballasted system

[maverick]

Hello Staggers.
Some help/advice please..I have luminition ,magnacore leads and believe everything to be in good order .however it seems not due to the followong problemsFor probably 2 years Ive experinced cold start problems,my choke is set up correctly as per the ROM and fuel flows freely into the filter.

Then last year taking Grandson to a car show quieing to get in for 15 mins the car stopped and would not restart ,10 mins later started fine.

On Saturday,started the car up and tried opening the petrol cap,the car started better but then began with a misfire on low revs reversed out of garage the car had been ticking over for 12 mins to thouroughly warm up before an anticipated drive.I turned off ignition to lock the petrol cap and she would not start until 10 mins later again.I hope that makes some sense and im hoping it is a coil problem as it starts missing when hot.

The coil,a bosch red top i bought in 2016 and am ashamed to say has only done about 4k miles.since

So any help on diagnosis and ignition coil brand recommendations and where to buy from would be very welcome,my car is mk1 and ballasted
,Thought I would start with something relatively inexpensive.
Mnay thanks in advance
Mark

[richardthestag]

so the circuit for your mk1 stag should be white/slate wire which should come from the back of the tachometer and go to one side of the white block ballast resistor, BUT you have luminition and the original mk1 tacho doesn't like electronic ignition and will cause the gauge to misbehave. So I wonder what has been changed on your setup already.

Then there will be a white orange wire which comes from the other end of the ballast resistor and goes to the ignition coil positive + terminal. White / orange should also come from the back of the starter motor solenoid and go also to the positive terminal on the ignition coil.



The idea behind a ballasted ignition coil setup is to run the car with a reduced voltage coil that needs a constant 9v ish feed which it gets from the ballast resistor. When starting, the starter solenoid - energised by holding the ignition key in the start position - will sent a battery feed to the ignition coil and give it more volts than it would normally get. this gives it a fighting chance to start the engine when the starter motor is drawing a huge amount of the battery current. As soon as you release the ignition key from the start position the white / orange feed from the starter solenoid returns to 0v and the ignition coil takes it's feed from the ballast resistor again and the coil doesn't over heat. Leave a 12v+ feed to a ballast coil and it will over heat quite quickly. run a non ballast ignition coil on a ballast supply and you will get a weak spark.

Are you any good with a multimeter? you should be able to diagnose the starter induced 12v boost to the ignition coil. The other job would be to test resistance of the primary and secondary coil windings.

When faced with a tired ignition setup I have sometimes found that jump starting the engine using a running engine pushes 13.# volts into the car being started. this will also get around a tired battery which cranking amps are too low to feed starter and ignition.

Misfire might be any one of a number of things, start with the luminition 3 pin connector which sits near the distributor. disconnect it, clean the contacts with an electric contact cleaner and reassemble.
Don't ignore fuel pressure, too low and it will not

Next distributor cap and rotor arm, what do the contact tips look like. even new from a number of sources are utter rubbish. stag specialists seem happy to sell them too

HT leads, do not assume that the lead is pushed fully home, use wd40 to lube the insulating cap up the ht lead, then click the lead onto both cap and plug before slipping the rubber insulating cap back over the contact

There will be a few along shortly to also complain about the bosch red top coil. I have no experience of them.

[maverick]

Hi Richard ,thanks for giving me such a detailed reply,I appreciate it,Iv replied to your questions in bold so the circuit for your mk1 stag should be white/slate wire which should come from the back of the tachometer and go to one side of the white block ballast resistor, BUT you have luminition and the original mk1 tacho doesn't like electronic ignition and will cause the gauge to misbehave. So I wonder what has been changed on your setup already.My tacho was converted by Spyda tach conversions

Then there will be a white orange wire which comes from the other end of the ballast resistor and goes to the ignition coil positive + terminal. White / orange should also come from the back of the starter motor solenoid and go also to the positive terminal on the ignition coil.


Hi Richard ,thanks for giving me such a detailed reply,I appreciate it

The idea behind a ballasted ignition coil setup is to run the car with a reduced voltage coil that needs a constant 9v ish feed which it gets from the ballast resistor. When starting, the starter solenoid - energised by holding the ignition key in the start position - will sent a battery feed to the ignition coil and give it more volts than it would normally get. this gives it a fighting chance to start the engine when the starter motor is drawing a huge amount of the battery current. As soon as you release the ignition key from the start position the white / orange feed from the starter solenoid returns to 0v and the ignition coil takes it's feed from the ballast resistor again and the coil doesn't over heat. Leave a 12v+ feed to a ballast coil and it will over heat quite quickly. run a non ballast ignition coil on a ballast supply and you will get a weak spark.

Are you any good with a multimeter?Ok with instruction you should be able to diagnose the starter induced 12v boost to the ignition coil. The other job would be to test resistance of the primary and secondary coil windings.Could yo please advise

When faced with a tired ignition setup I have sometimes found that jump starting the engine using a running engine pushes 13.# volts into the car being started. this will also get around a tired battery which cranking amps are too low to feed starter and ignition.
Bosch battery good,with high torque starter

Misfire might be any one of a number of things, start with the luminition 3 pin connector which sits near the distributor. disconnect it, clean the contacts with an electric contact cleaner and reassemble.
Don't ignore fuel pressure, too low and it will not

Next distributor cap and rotor arm, what do the contact tips look like will check. even new from a number of sources are utter rubbish. stag specialists seem happy to sell them too

HT leads, do not assume that the lead is pushed fully home, use wd40 to lube the insulating cap up the ht lead, then click the lead onto both cap and plug before slipping the rubber insulating cap back over the contact

There will be a few along shortly to also complain about the bosch red top coil. I have no experience of them.

Many thanks Richard.
Mark

[Wheelz]

I have used Intermotor 11070 ballast coils and they seem to be good. Available in all the usual places. (ebay etc).

[maverick]

I have used Intermotor 11070 ballast coils and they seem to be good. Available in all the usual places. (ebay etc).

Many thanks wheels,at least thats one recommend ,its a start

[richardthestag]

how do you know it is the coil causing the issue maverick ?

But while we are believing coil to be at fault I would simplify the circuit, loose the ballast resistor and install a pertronix flame thrower. not sure which version you need to work with your luminition electronics. Someone like Distributordoctor will be able to sell the coil and also the correct one for the application.

to test your coil there are a few instructional videos on youtube to show you how to test the primary and secondary windings of the coil. you will need to research first to find out what your coil should have.

[Wheelz]

If you ditch the ballast fit a Flamethrower 3 ohm coil, not the 1.5 ohm or the very low resistance Flamethrower II.

[maverick]

how do you know it is the coil causing the issue maverick ?

But while we are believing coil to be at fault I would simplify the circuit, loose the ballast resistor and install a pertronix flame thrower. not sure which version you need to work with your luminition electronics. Someone like Distributordoctor will be able to sell the coil and also the correct one for the application.

to test your coil there are a few instructional videos on youtube to show you how to test the primary and secondary windings of the coil. you will need to research first to find out what your coil should have.

Hi Richard
starting with the coil as its an inexpensive place to start,I think I will stick with the ballast as I dont know how to remove it

Many thanks for your input

[maverick]

If you ditch the ballast fit a Flamethrower 3 ohm coil, not the 1.5 ohm or the very low resistance Flamethrower II.

Thanks wheels,if i can find out how to remove the ballast I will consider the flamethrower,do they have a good reputation for reliability?

Thanks alot
cheers Mark

[Goldstar]

If you ditch the ballast fit a Flamethrower 3 ohm coil, not the 1.5 ohm or the very low resistance Flamethrower II.

The 0.6ohm is the correct coil for the flamethrower 2

[Wheelz]

Thanks wheels,if i can find out how to remove the ballast I will consider the flamethrower,do they have a good reputation for reliability?

Thanks alot
cheers Mark

I haven't used them but you could ask Richard.

I would keep the ballast and fir an Intermotor 11070 ballast coil. I just bought one to keep in the boot as a spare.

[richardthestag]

Chris' solution is the easiest, straight swap. I have a very old and very used intermotor ignition coil which is probably nearly 30 years old. refuses to show anything other that good service, now in my big box of test stuff.

Alas like so many of the solid brand names from the past, quality today may not necessarily be the same. Suck it and see. keep the receipts.

One thing I did read in your response that just caught my eye, high torque starter! does it even have the connector to give the white/orange boost to the ignition coil? If you only have the big black battery lead and a white/red wire connected to your starter motor then your ballast resistor will be utterly useless at helping you when starting. I doubt that it would cause the misfire but it would make the engine more difficult to start, especially from cold.

Did you check the luminition connector near this distributor? A loose or dirty connection is going to create havoc.

There have been a few threads here about misfire recently, well worth you reading through those to see if anything new to try. Your ignition coil is mounted in a hostile location, doesn't get much warmer and even more so if you have upgraded* your cooling fan to electric and removed the viscous fan. It is essential that it is clear on all sides but especially the bottom of the coil. If it is sitting on the engine block it will very quickly over heat.

When chasing down an intermittent issue like this it pays to be methodical in your approach, change one thing at the time and see if it fixes the issue before moving on. Can be time consuming but it saves you having a box full of nearly new bits that you have removed from your car and no idea as to which part caused the issue.

The best time to diagnose an issue is at the point it fails you. Not so easy when you are miles from home. Carry with you some basic tools and if you are in a safe location etc then they may help.

When it fails is the fuel filter empty? Does the engine bay stink of fuel?

A set of jump leads and a running car pushing 13.whatever volts into your stag electrics might make it easier to start, as might a decent battery jump pack.

if you have a ignition timing strobe they are very handy and convenient to tell you if you are getting a high tension spark, connect it to the king lead - coil to distributor cap - and crank the engine you should get a good steady stream of flashes from the strobe with no "untidy" gaps, if the flashes are intermittent then the coil cannot keep up with demand and is failing, but don't discount the wiring to and from the ballast resistor, the ballast resistor itself or the trigger from the luminition. If the king lead test works try one of the plug leads, should be one flash for each complete revolution of the engine but it need to be consistent, i.e. flash, 3 seconds, flash, 3 seconds etc etc. again if inconsistent then you have an ignition or supply issue.

Try not to mess around with HT leads with the ignition on, give you quite a shock and make you curse.

Lastly but by no means least, it happens that ignition related faults seem to end up being cured by fixing the fuel system and vice versa

[maverick]

I haven't used them but you could ask Richard.

I would keep the ballast and fir an Intermotor 11070 ballast coil. I just bought one to keep in the boot as a spare.

Thank you Chris,
Ive ordered an intermotor coil from local motorfactor.,and will report back when fitted
Appreciate your input
Mark

[maverick]

Chris' solution is the easiest, straight swap. I have a very old and very used intermotor ignition coil which is probably nearly 30 years old. refuses to show anything other that good service, now in my big box of test stuff. Hi Richard,Wish the quality was as good as 30 yrs ago

Alas like so many of the solid brand names from the past, quality today may not necessarily be the same. Suck it and see. keep the receipts.

One thing I did read in your response that just caught my eye, high torque starter! does it even have the connector to give the white/orange boost to the ignition coil? If you only have the big black battery lead and a white/red wire connected to your starter motor then your ballast resistor will be utterly useless at helping you when starting. I doubt that it would cause the misfire but it would make the engine more difficult to start, especially from cold.That is avery good point ,I fitted it but cant remember the wiring so i will check


Did you check the luminition connector near this distributor? A loose or dirty connection is going to create havoc.Will check

There have been a few threads here about misfire recently, well worth you reading through those to see if anything new to try. Your ignition coil is mounted in a hostile location, doesn't get much warmer and even more so if you have upgraded* your cooling fan to electric and removed the viscous fan. It is essential that it is clear on all sides but especially the bottom of the coil. If it is sitting on the engine block it will very quickly over heat.
Coil is mounted about 2 inches above block

When chasing down an intermittent issue like this it pays to be methodical in your approach, change one thing at the time and see if it fixes the issue before moving on. Can be time consuming but it saves you having a box full of nearly new bits that you have removed from your car and no idea as to which part caused the issue.

The best time to diagnose an issue is at the point it fails you. Not so easy when you are miles from home. Carry with you some basic tools and if you are in a safe location etc then they may help.

When it fails is the fuel filter empty? Does the engine bay stink of fuel?

Fuel filter is half full when cranking,after 1 prelonged cold starting session i had a plug out and it was dry,no overly smell of fuel

A set of jump leads and a running car pushing 13.whatever volts into your stag electrics might make it easier to start, as might a decent battery jump pack.

if you have a ignition timing strobe they are very handy and convenient to tell you if you are getting a high tension spark, connect it to the king lead - coil to distributor cap - and crank the engine you should get a good steady stream of flashes from the strobe with no "untidy" gaps, if the flashes are intermittent then the coil cannot keep up with demand and is failing, but don't discount the wiring to and from the ballast resistor, the ballast resistor itself or the trigger from the luminition. If the king lead test works try one of the plug leads, should be one flash for each complete revolution of the engine but it need to be consistent, i.e. flash, 3 seconds, flash, 3 seconds etc etc. again if inconsistent then you have an ignition or supply issue.
I dont have a timing strobe,but will keep this info incase car needs external help ,ie garage,but im hoping to sort this my self,Ive had the car for 24 yrs and overcome alot of problems with the help of the great people on the forum,which leads me onto saying thank you very much for taking the time and thought for all your suggestions,it is much appreciated

Try not to mess around with HT leads with the ignition on, give you quite a shock and make you curse.

Lastly but by no means least, it happens that ignition related faults seem to end up being cured by fixing the fuel system and vice versa

Will progress with the suggestions and report back
Regards Mark

[jbuckl]

I found that the power supply to the fuel pump was not 100% because it had been piggy backed to power the electronic ignition.

separate supply fixed the misfires cutting out issues.

on the coil topic, Bosch red top lasted 4 years.

viper dry resin has been ok since then …. But not plain sailing…. Bought 2.

1 was duff!