Starting problem

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barry young
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Starting problem

Postby barry young » Sat Apr 27, 2019 1:08 pm

I've had a starting problem this week, but once started it runs fine. I can hear the petrol pump ticking over, it's had a new coil, leads, points and condenser in the last few months. Just tried one of those flashing spark plug testers and found a very weak spark which suddenly gets much stronger when the engine bursts into life. Any ideas anyone?

pgp001
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Re: Starting problem

Postby pgp001 » Sat Apr 27, 2019 2:44 pm

From what you describe, it could be your battery voltage is low and affecting the spark strength, then once you get it started the charging system keeps the voltage higher and a better spark.

Check your voltage with a multimeter, the battery should give about 12.6 volts when the engine is not running, and about 14.5 volts when it is. If the battery is on its last legs, the voltage will drop significantly when you use the starter motor and it may be insufficient to give you a good spark.

Do you have a starting handle ?
If it starts easily on the handle, that would go some way to confirming the above.

Or do you have another battery to try, or a set of jump leads to add a second battery from another car.

Phil

oliver90owner
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Re: Starting problem

Postby oliver90owner » Sun Apr 28, 2019 9:54 pm

An alternative to Phil’s suggestion could that the starter motor is taking too much current.

One expects a lower battery voltage while cranking. That is why Fords added a ballast resistor to the ignition system back about 1970 and changed to 6 volt coils. It likely allowed easier stating while they could fit a smaller capacity battery. Your flashing spark plug tester might well have always provided less light until the engine has started, or the rpm increased above the after-glow time of the device.

Checking the tester light output, while hand cranking, would soon sort out that possibility.

Trickydicky
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Re: Starting problem

Postby Trickydicky » Mon Apr 29, 2019 7:02 am

Your battery could be on its way out,a simple test is to connect a multi meter across the battery and check the voltage drop while starting the car. Anything below 9v and I would suggest a new battery.
Richard

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oliver90owner
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Re: Starting problem

Postby oliver90owner » Tue Apr 30, 2019 6:51 am

Trickydicky wrote:
Mon Apr 29, 2019 7:02 am
Your battery could be on its way out,a simple test is to connect a multi meter across the battery and check the voltage drop while starting the car. Anything below 9v and I would suggest a new battery.
Please don’t jump to conclusions or you may finish up replacing both stater motor and battery before fixing the problem. Sort out which is at fault, and then make the fix. That is why they make battery testers - a simple multimeter voltage reading does not necessarily tell you anything.

Might, for all we know, just need the battery recharging properly, to be able to start easier - and the problem is in the charging circuit (loose fan belt, dodgy control box, failing dynamo/alternator, poor connections, etc)

pgp001
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Re: Starting problem

Postby pgp001 » Tue Apr 30, 2019 7:00 am

One thing my dad taught me to do many years ago was to remove the battery leads from the battery and clean them and the posts on the battery itself.
Before reconnecting them smear them with Vaseline/Petroleum Jelly. This helps prevent a high resistance connection which could account for a big voltage drop when running the starter motor.

That is one thing you can try for free. :D

Phil

myoldjalopy
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Re: Starting problem

Postby myoldjalopy » Tue Apr 30, 2019 9:00 am

I think if the battery was actually faulty to the extent that it can't easily generate a good spark, it would have given up turning the engine over by now. The OP says he had starting problems during the week and suggests that the engine turns over OK, just takes a while to start. If the battery was the culprit, surely it wouldn't be able to keep turning the engine over? With no updates from Barry on the suggestions offered so far, however, we are forced to guess at these things. But, for starters, I would clean and vasoline the battery posts, as Phil suggested. It could also be a poor connection at the starter motor, it could be something else but we need feedback to eliminate certain things and home in on the real issue.

Trickydicky
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Re: Starting problem

Postby Trickydicky » Tue Apr 30, 2019 1:38 pm

oliver90owner wrote:
Tue Apr 30, 2019 6:51 am
[quote=Trickydicky post_id=637773 time=<a href="tel:1556517728">1556517728</a> user_id=15158]
Your battery could be on its way out,a simple test is to connect a multi meter across the battery and check the voltage drop while starting the car. Anything below 9v and I would suggest a new battery.
Please don’t jump to conclusions or you may finish up replacing both stater motor and battery before fixing the problem. Sort out which is at fault, and then make the fix. That is why they make battery testers - a simple multimeter voltage reading does not necessarily tell you anything.

Might, for all we know, just need the battery recharging properly, to be able to start easier - and the problem is in the charging circuit (loose fan belt, dodgy control box, failing dynamo/alternator, poor connections, etc)
[/quote]
If you read my post it says “could” and “I would suggest” they are not words that say your battery is faulty, they are advising to check.
Richard

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Edward1949
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Re: Starting problem

Postby Edward1949 » Wed May 01, 2019 2:56 pm

barry young wrote:
Sat Apr 27, 2019 1:08 pm
a very weak spark which suddenly gets much stronger when the engine bursts into life. Any ideas anyone?
I'm no electrical expert, and this is a (very) long shot....it could be that your car has been fitted with a ballast resistor in the past. If the wiring has been transposed so that the ballast resistor cuts in during starter motor operation and cuts out during normal running - in other words the exact opposite of what it should be doing, then these symptoms make a lot of sense.

oliver90owner
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Re: Starting problem

Postby oliver90owner » Wed May 01, 2019 11:46 pm

Hmmm, let me respond to the last two posts.

Firstly, providing a “simple test” that gives a definitive diagnosis is totally flawed when that test does not necessarily provide a definitive result. Let me say again a simple voltage test under unknow load conditionsbisbworthless.

I’m sorry but you do not seem to understand the basic rudiments of fault diagnosis.

The battery is the prime suspect - make no mistake about that - but there are other possibilities which need to be eliminated within that diagnosis process. Just using a voltage without a fixed load is useless - if the starter motor were taking twice its normal current, the same low voltage could well be found!

Now to the ballast resistor being in circuit during starting and out of circuit when running. Totally out of the question, I would suggest, because the coil would burn out in a very short time, if that were the case! Or at least the points would not last long as they would be switching a far too heavy current.

Just think about it the coil would be a six volt unit to run with a ballast resistor. If a 12 volt coil is installed, the lower spark energy, while cranking, would be halved during cranking, quite likely resulting in no start or poor starting all the time when the battery volts are obviously lowered while cranking.

Try running an engine with only a 6 volt supply to a 12 volt coil. A very unsatisfactory situation.

kennatt
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Re: Starting problem

Postby kennatt » Thu May 02, 2019 7:04 am

well there's starting problems and starting problems(no further contact from OP after 5days) the essential question is ... is the problem because the engine is turning over too slow,indicating battery or starter motor,or is it spinning at normal rate and taking time to fire up indicating ignition ,fuel or compression issues. OP needs to contact with further information.

Edward1949
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Re: Starting problem

Postby Edward1949 » Thu May 02, 2019 10:12 am

oliver90owner wrote:
Wed May 01, 2019 11:46 pm

Now to the ballast resistor being in circuit during starting and out of circuit when running. Totally out of the question, I would suggest, because the coil would burn out in a very short time, if that were the case! Or at least the points would not last long as they would be switching a far too heavy current.

Just think about it the coil would be a six volt unit to run with a ballast resistor. If a 12 volt coil is installed, the lower spark energy, while cranking, would be halved during cranking, quite likely resulting in no start or poor starting all the time when the battery volts are obviously lowered while cranking.

Try running an engine with only a 6 volt supply to a 12 volt coil. A very unsatisfactory situation.
Retro-fitting a ballast resistor was a popular cheap cold-start cure in the seventies and eighties for ageing vehicles with non-electronic ignition (incidentally the ballast coil was typically 9V). I am proposing an (admitted unlikely) scenario where a new owner recommissions an old car with a 12v coil, fails to spot that it has been fitted with a ballast resistor, and rewires it so that the resistor applies only as starter operates (ie opposite to what it should be). Result: very weak spark during starting (12v coil ballasted down to 9v), normal spark during running. Which fits conveniently with the symptoms described.

simmitc
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Re: Starting problem

Postby simmitc » Thu May 02, 2019 1:57 pm

Entirely plausible, and in-keeoing with the period "improvement" such as disc brakes and servos, heated rear screens and hazard lights, even radial tyres - new cars had them, so Minor owners modified older cars to match. I hqave one scrap car sitting outside at the moment that I modified to coil + ballast about 1980, so I expect that there are others out there too. Whether it applies in this case remains to be seen, but it's a good idea of Edward's. Other suggestions for more likely causes are also good places toi look, but as observed by others, we need some feedback from the OP.

barry young
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Re: Starting problem

Postby barry young » Sat Jun 29, 2019 4:00 pm

Thanks for all the replies. At the time of this post it n April, I followedd the advice and charged the battery and didn't have any problem until last week. Now the same things happenng with a fully chag d battery. Ive started a new post on this too b cause I also realised I had a manifold leak and wondered if that was involved.
Had this car for 25 years so if there had bren a balast resistor fitted, it might have come to light before now - sometimes this is daily driving car.
Ive cleaned battery connections.

alawrence10360
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Re: Starting problem

Postby alawrence10360 » Tue Jul 30, 2019 9:26 pm

pgp001 wrote:
Tue Apr 30, 2019 7:00 am
One thing my dad taught me to do many years ago was to remove the battery leads from the battery and clean them and the posts on the battery itself.
Before reconnecting them smear them with Vaseline/Petroleum Jelly. This helps prevent a high resistance connection which could account for a big voltage drop when running the starter motor.

That is one thing you can try for free. :D

Phil]
You should only apply battery grease/silicone/ petroleum jelly/ vasaline AFTER you have cleaned the battery terminal / connection and connected it to the battery
These materials are actually very good insulators and have a high electrical resistance
They are used to reduced to prevent oxidation
These days there are very good sprays available which are easy to apply and prevent corrosion

alawrence10360
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Re: Starting problem

Postby alawrence10360 » Tue Jul 30, 2019 9:26 pm

pgp001 wrote:
Tue Apr 30, 2019 7:00 am
One thing my dad taught me to do many years ago was to remove the battery leads from the battery and clean them and the posts on the battery itself.
Before reconnecting them smear them with Vaseline/Petroleum Jelly. This helps prevent a high resistance connection which could account for a big voltage drop when running the starter motor.

That is one thing you can try for free. :D

Phil]
You should only apply battery grease/silicone/ petroleum jelly/ vasaline AFTER you have cleaned the battery terminal / connection and connected it to the battery
These materials are actually very good insulators and have a high electrical resistance
They are used to reduce/prevent oxidation
These days there are very good sprays available which are easy to apply and prevent corrosion
Last edited by alawrence10360 on Wed Jul 31, 2019 6:52 am, edited 1 time in total.

pgp001
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Re: Starting problem

Postby pgp001 » Tue Jul 30, 2019 11:05 pm

Good point, that makes sense.

Phil

IslipMinor
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Re: Starting problem

Postby IslipMinor » Wed Jul 31, 2019 5:55 pm

Yes, it IS a very good point!

My son is involved with the local Sailability charity in Oxford, which teaches disabled people to sail. They have a 1949 Ferguson TEA20 tractor (the ubiquitous 'little grey Fergie!) to tow the boats about, and it blew its head gasket a couple of weeks ago. After getting the head skimmed and buying new gaskets, hoses, thermostat etc., and rebuilding the engine, we went to start it and no sign of life from the battery - a voltmeter check across the battery lead clamps showed 0 volts.

Connecting the jump leads to his Discovery battery, the engine started instantly and ran very nicely, so we decided to drive around the large sailing club car park to warm the engine up, so that we could re-torque the head stud nuts and reset the tappets. After that, again no volts from the battery leads, BUT 12.6v across the battery posts - there is a clue there!

Removed the two leads, to find very dry connections, so cleaned the inside of the clamps and the battery posts, applied a smear of grease (did not have Vaseline to hand), and battery voltage restored as it should be.
Last edited by IslipMinor on Thu Aug 01, 2019 8:49 am, edited 1 time in total.
Richard



kennatt
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Re: Starting problem

Postby kennatt » Thu Aug 01, 2019 8:34 am

have you ever had a compression test done,I take it the engine is spinning over at a satisfactory rate. I would get a test done just in case, with low compression it will always be difficult to start from cold.
Last edited by kennatt on Thu Aug 01, 2019 8:36 am, edited 1 time in total.


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