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Help Please - No Spark!!


lil-nicky
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Hi,

 

This is my first post so please bear with me!  I have a 1971 Spitfire Mk IV that I'm slowly but surely restoring.  Bodywork is done and up until about November last year the engine was running relatively smoothly.  Then it stopped.  Dead.  Wouldn't turn over - nothing.

 

Now I've come back to the car after a break and decided I need to get her started before doing anything else.  She hasn't seen the road since 1994 so everything is being replaced anyway but I really want to get to the bottom of the starting issue.  So far I've replaced the following and I now have an engine that will turn over but no spark:

 

New Plugs

New HT Leads

New New Dizzy Cap

New Accuspark electronic ignition

New Coil

New Starter motor solenoid

Recon Starter Motor

Replaced wire from coil to ignition

New ignition barrel

Nearly new battery

New rotar arm.

 

Now I'm getting 12 volts to the distributor cap when I turn the ignition, but nothing past there.  I struggle with the dark art of electrics at the best of times but this has me totally lost!!  I've tried searching the forum and found a couple of posts but tbh they could be written in dutch!  Ohms, Volts, ballast thingies are a mystery to me but I refuse to give up and will  sort this myself! 

 

So basically, if anyone could be kind enough to take the time to consider the problem, offer any solutions and perhaps provide a brief glossary for dummies I'd be forever in your debt!!

 

 

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The mkIV has normally got a ballasted coil feed this is a resistance wire in the loom , its a dull white pink colour this feeds the coil and your electronice unit ,, from the ign key switch the wire drops the coil voltage to around 6 volts, its not easy to check but if you earth the coil negative then check the readings

it may be the low voltage is not liked by the dizzy electronics , some wont work below 8volts

 

there is a second wire from the starter solenoid that by passes the ballast wire when you crank the starter, this puts 12v direct to the coil to aid starting in poor battery condition.

 

to get the car to start both these circuits need to work

 

if you have a meter check the ohms across the coil blade terminals

 

if its 3 ohm you need a 12v feed all the time

if its 1.5 ohms it must have the dropper wire in use and make up a 12v feed for the dizzy electronics

 

if its got a 3 ohm coil and has been ballast bypassed to 12v this is the easiest option as the dizzy electronics will have a 12v feed , not a 6 volt feed which can be too low.

 

Not sure tbat makes any sense

 

Pete

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Are you getting a spark at the spark plugs?

 

Try pulling one of the plugs and holding it against the block while cranking the engine.

 

You should get a spark across the base of the plug.

 

If not try the same technique, but with the HT lead unplugged from the top of the plug, and see if you get a spark between the lead and plug.

 

If both of these work, then power is reaching the plugs, and either your timing is completely out, i.e. Distributor installed 180 degrees out, or there is no fuel reaching the cylinders.

 

I went through similar issues earlier in the year, and with Pete's advice traced it to dirty plugs, so I feel your pain.

 

Karl

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I'm with Pete on the 6v 12v issue Accuspark are not the best so if you do have the 6v set up I don't think it will work You may also have a new 3 ohm coil but still the resistive wire replace the coil feed with a temporary from the battery Then see if you get a spark

 

Do check which coil you have it won't be happy with a perm 12v use this only as a test

 

 

Aidan

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Surely the ballasted coil idea was another of Triumph's penny pinching ideas?

Fit a cheap coil, fit only for 6V and blast it with 12V to help starting.

 

And equally surely, the answer today is get a proper coil and junk the ballast!

Simples!

John

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For Nicky's information, the ballasted system was designed to aid cold starting. 12v across a 6v coil provides a bigger spark for the short period of starting the engine. This was considered beneficial in an era when batteries weren't as good as now and weather colder. Maybe unnecessary these days, unless you live in Scotland!  :lol:  I have a ballasted system, it works fine, I see no reason to change it. 

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I disagree with John. A ballasted system costs more to produce/install.

 

When even a new battery cranks an engine over it suffers considerable voltage drop, usually down to 9V.

 

So in a non-ballasted system, it is getting under 75% of normal voltage, and will make for a weaker spark, at the worst time possible.

 

A ballasted system will provide approx 150% of normal voltage (not good long term, but fine just for cranking) to give a nice fat spark when needed. A clever solution, as simple and effective.

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Thankyou all - I've already done the checks for a spark against the block etc and theres nothing.  I'm going back to basics until I figure out the problem so I've ordered new points and a ballast resistor.  I'll swap out the accuspark and see how that goes.  Then I'll try the resistor.  The coil was as listed for the car from SC Parts - 12v ballasted 1.4 ohms.  Means nothing to me so I had to go with what was listed for the car.  Oh and just in case it is the accuspark I've contacted the supplier and they've put a replacement in the post today.  Cross your fingures for the weekend....

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Did you tell Accuspark you had a ballasted system? I have an Aldon electronic ignition and it is specifically for the ballasted system. I assume Accuspark also have different versions.

 

Earlier in the thread Pete Lewis mentions mk4 has a resistive WIRE, dull white with a feint pink strip. Not sure if that's right as a mk4 diagram I've seen say RESISTOR. Pete is normally right but he's off on holiday and demob happy!  :lol: If you have the wire you will find one end on the ignition switch the other end can go to either the coil, or the starter solenoid. 

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Im watching you , cottage in north yorks with full glass bedroom , a quick flash and the sheep all run away

 

ha !

 

ive got two mk IV in my area and both white pink ballast wires which had to be bypassed or changed to get 12v to the aldon we fitted.

 

If theres a ceramic its pretty obvious the weedy coloured white pink is lesser.

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I am having almost identical problems trying to get a PowerSpark high energy dizzy, coil and leads to work in a 1971 GT6.  None of the wiring looms that I have seen bear any relation to the loom in my car but I eventually found the dull white/pink trace ballast resistance wire spliced into the loom.  It starts by joining the white/pink trace to a white wire at a small pigtail sticking out the loom near the battery and fuse panel on the bulkhead.  It ends at another pigtail sticking out the loom close to the alternator and ignition coil where the white/pink trace joins with a white/yellow trace.  The white/yellow trace is then the only connection to my ignition coil "+" terminal.  Despite by-passing this ballast resistance to feed a Viper coil my PowerSpark system refuses to operate.

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On your ballasted system white/yellow is the connecting wire between the starter solenoid and coil. The solenoid provides 12volts, briefly as the engine starts. Once the engine is running there is no 12volts from the solenoid.

 

The white wire is the top of one of the fuses and fed from the ignition switch. It's at 12 volts while the engine is running. So the white/pink connected between these two is correct and would provide 6v on the white/yellow when the engine is running. If the Viper coil is 12v un-ballasted, bypassing the white/pink should work. So I suspect there's something not right with your Powerspark.

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On your ballasted system white/yellow is the connecting wire between the starter solenoid and coil. The solenoid provides 12volts, briefly as the engine starts. Once the engine is running there is no 12volts from the solenoid.

 

The white wire is the top of one of the fuses and fed from the ignition switch. It's at 12 volts while the engine is running. So the white/pink connected between these two is correct and would provide 6v on the white/yellow when the engine is running. If the Viper coil is 12v un-ballasted, bypassing the white/pink should work. So I suspect there's something not right with your Powerspark.

 

Already had a replacement electronic module for the dizzy and a replacement coil but still no joy.

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The Accuspark and similar products in my experience are pretty dire, they're cheap for a reason. Most electronic ignition modules should work fine with a ballasted system if the power supply to the module is taken from a 12v feed that is live during cranking (so nothing connected to the accessory feed on the switch) and not the positive on the coil as this drops to 6v after starting. Most people pick up the live on the coil for convenience, but obviously not a good idea on a ballasted set-up.

 

Darren

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Hola!

 

I've plumbed in the ballast resistor today and checked all my connections etc and... no joy.  Still nothing.  Just absolutley no power past the distributor cap.  The cap is new as is the rotar arm and I've swapped to new points until I can get her running but still no success.  So my next thought is to strip out the 40 year old wiring for the part of the car and replace it.  Any thoughts?  Anyone know where I can buy the correct wire from to replace the old stuff?

 

LN

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There are issues using a 6 V coil on an Accuspark with the ballast resistor bypassed.This is because the current through the power switch section of the device may be too high and therefore could possibly cause damage.

 

Basically with 1.4 ohms of the 6 volt coil is too low a resistance. Either retain the ballast resistor or fit a 12 volt coil.

 

The  Accuspark device itself should be fed from 12 V ignition feed and the 6 volt coil through the ballast resistor from the 12 v ignition feed.

 

If a 12 V coil is fitted then the ballast resistor can be bypassed.

 

Dave

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I notice you previously said   "Now I'm getting 12 volts to the distributor cap"    You should not be getting 12volts to the cap! The cap distributes the HT, (High Tension, meaning very high voltage)  between the coil and the plugs. If you do have 12 volts on the cap, then the wiring's wrong.

 

You should be getting LT, (Low Tension  12 or 6 volts)  on the small + terminal connector on the coil. The - terminal connector on the coil connects to the  points or electronics in dizzy and, when working, fluctuates between 12volt (Or 6volts) and ground. 

 

Are you getting a spark out the coil? What comes out the distributor cap for the plug wires is only what comes out the coil, shuffled around between the plugs. You could attach a plug to the heavy output wire of the coil, short it to ground and see if there's a spark when you turn the engine. If there is, your electronics/points are OK and the cap is the problem. 

 

To test the cap, take the heavy wire off the coil and attach you meter wire to the heavy wire. Then take a plug wire off at a plug and attach the other meter wire to the plug heavy wire. Using the ohms range the dial should jump around when you turn the engine over.

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A daft question: your new plug lead set, have you checked them for continuity? Why I ask, going back about 5 years, I fitted a new set of leads and the car would NOT fire up. To cut a long story short, there was a break internally in the middle of the coil-to-distributor lead. It was only by chance that I tried turning the engine over and could actually hear an intermittent "tick" from it. I re-fitted the old lead and bingo, we were back on line. It taught me a lesson, don't assume new=o.k. Also beware of introducing new problems!

You WILL crack this...

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this reminds me of a guy at work who was always after some clues an never listened to advice, 

he had a Vx Victor  so in desperation told him to stick the HT lead in his mouth and turn the engine over to find TDC

 

next morning had to get security to remove him ...so dont try this at home think he was mentally scared for a long time ,

 

this doesnt help much but cant stick anymore ruddy poldark

 

Pete

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