126 replies to this topic

[Yoda]

How many times, do we go to a customer with "major issues" only to find lack of knowledge and poor maintenance is the actual problem. Not the assumed offending item. LOL

[Tamworthbay]

To be fair to the OP I think a lack of info from the supplier is often at fault. They have a car that is running fine but want to 'upgrade'. Because they supplier wants to sell as many units as possible they conveniently forget to mention common problems, the buyer gets it and it doesn't work because of unknown issues. Faults like earthing issues can be a beggar to find for even experienced mechanics/ auto electricians. Although in this case it sounds Possible the supplier doesn't fully understand his product which is strange. Perhaps the guy who looked at it is the 'weekend guy' and the boss would have spotted it straight away. Without more info I thinks it's only fair to give the benefit of the doubt to the Op and the supplier.

[Captain Mainwaring]

It's how I make my money - dealing with customers who are incapable of running their equipment and decide they aren't going to part with the retention money. Can be quite a challenge when there is a million quid outstanding.

[Yoda]

Yes, so lack of knowledge also applies to the supplier, but surely if the weekender fails to realise the voltage issue, then the supplier should have at least asked the question right at the start, but hey! like you say, lets give the benefit of the doubt for now.

[Captain Mainwaring]

To be fair to the OP I think a lack of info from the supplier is often at fault. They have a car that is running fine but want to 'upgrade'. Because they supplier wants to sell as many units as possible they conveniently forget to mention common problems, the buyer gets it and it doesn't work because of unknown issues. Faults like earthing issues can be a beggar to find for even experienced mechanics/ auto electricians. Although in this case it sounds Possible the supplier doesn't fully understand his product which is strange. Perhaps the guy who looked at it is the 'weekend guy' and the boss would have spotted it straight away. Without more info I thinks it's only fair to give the benefit of the doubt to the Op and the supplier.

 

The fitting guides are very vague, no minimum voltage mentioned etc - they bring heartache on themselves.

Better have no one on duty than someone who doesn't have much clue what he is looking at.

[Yoda]

Yes, and i also make my money with customers who get so far and give up. Then they come to me LOL

[Yoda]

Just had a read back, now i am picturing a Mini driving down the road with a guy on foot with battery and jump leads, running behind the car!!!!

 

Sorry, just thought i would share the piccy in my mind.

[KernowCooper]

Just had a read back, now i am picturing a Mini driving down the road with a guy on foot with battery and jump leads, running behind the car!!!!

 

Sorry, just thought i would share the piccy in my mind.

Yes made me laugh that

[lrostoke]

Think I would put the battery on charge, check all earth and main battery connections then go from there.

 

Although I would imagine 10v under cranking conditions isn't to far out...isn't that the whole point of the ballast system and the byepass wire for starting..to overcome the low voltage when cranking.

 

In a nutshell the problem seems to be this

 

With the dizzy set to a position where the car runs well, in that position it will barely turnover on the starter.

 

retarding the dizzy so it will turn over and the car won't start.

[Captain Mainwaring]

Think I would put the battery on charge, check all earth and main battery connections then go from there.

 

Although I would imagine 10v under cranking conditions isn't to far out...isn't that the whole point of the ballast system and the byepass wire for starting..to overcome the low voltage when cranking.

 

In a nutshell the problem seems to be this

 

With the dizzy set to a position where the car runs well, in that position it will barely turnover on the starter.

 

retarding the dizzy so it will turn over and the car won't start.

 

No, you've still not got it.

He isn't running ballast and he has only 8V at cranking.

The ignition unit may nominally run on up to 14.2 Volts if the alternator is doing it's job OK, yet the OP is expecting it to put a hot spark in the right place at the right time by only giving it 8V (55%) of it's normal running voltage? 

It isn't going to happen with a cheap aftermarket unit - this has been done to death on aftermarket units for motorbikes - they won't start if the battery is below par on an electronic unit whereas they can still be fired up on points.

 

If the OP is interested in proving or disproving the point, then he can carry out a dead simple test. Give the ignition unit an external supply from a spare battery or another car - link the two chassis together with a jump lead (doesn't need to be heavy) and then give the powerspark a +ve feed (ideally with a fuse for safety) from the external source and the start the thing. Do NOT parallel the external power with the car battery..

 

Low voltage has already be shown, prove or disprove that it's the cause of the problem, then fix the low voltage issue. 

Anything else is a waste of time and it's not entirely fair to rubbish the equipment sold when it's not being installed properly.

[lrostoke]

 

No, you've still not got it.

He isn't running ballast and he has only 8V at cranking.

The ignition unit may nominally run on up to 14.2 Volts if the alternator is doing it's job OK, yet the OP is expecting it to put a hot spark in the right place at the right time by only giving it 8V (55%) of it's normal running voltage? 

 

 

Yes but when cranking you don't get 14.2v, you have 12 -12.6v depending on battery less whatever the starter is sucking out of it. I believe when cranking this can drop to 9 or 10volts. Which is what he's getting.

You'll only get above 12.6v when the engine actually kicks in and the alternator starts doing its thing.

[Captain Mainwaring]

 

 

No, you've still not got it.

He isn't running ballast and he has only 8V at cranking.

The ignition unit may nominally run on up to 14.2 Volts if the alternator is doing it's job OK, yet the OP is expecting it to put a hot spark in the right place at the right time by only giving it 8V (55%) of it's normal running voltage? 

 

 

Yes but when cranking you don't get 14.2v, you have 12 -12.6v depending on battery less whatever the starter is sucking out of it. I believe when cranking this can drop to 9 or 10volts. Which is what he's getting.

You'll only get above 12.6v when the engine actually kicks in and the alternator starts doing its thing.

 

 

I never said you did. It's quite clear in what I wrote. 

 

The ignition unit may nominally run on up to 14.2 Volts if the alternator is doing it's job OK, yet the OP is expecting it to put a hot spark in the right place at the right time by only giving it 8V (55%) of it's normal running voltage? 

 

Yes, I think powerspark are nowhere near clear enough in their literature, but that doesn't change the fact that the OP needs to find out why he only gets 8V cranking - it's up to him if he wants to try the solutions offered, but for the moment I don't think he can blame powerspark for his issues until he sorts out the problem.

 

If the OP has jumped up and down and said his powerspark had gone t1ts up and then conceded that his alternator had overcharged to 16V, then everybody would be nodding their heads, after all, that's 4V out of spec isn't it? 

 

Go 4V the other way is equally out of spec, yet for some reason the powerspark is supposed to tolerate it.

 

I'd put a pint of cider on it that if the OP lays on a temporary supply then things will start working properly, and a further pint that if he doesn't, come the cold weather, he may be doing a couple of bump starts.

[lrostoke]

 

We measured the volt drop on cranking.  With the new dizzy in place we got about 8 volts.  With the new dizzy,  in a retarded stance (or the old dizzy as per normal timing) it was 10.3v.   The mech enentually gave up and said he didn't know what to suggest. 

 

 

Thats the bit that doesn't make sense to me, he says with his old points dizzy correctly timed the voltage dropped to 10.3v   that sounds to be a normal sort of voltage drop when cranking.

 

With the powerspark fitted it drops to 8v, but goes upto 10.3 if they retard it so much it won't start...

[KernowCooper]

Something odd very odd as Steve said above going on with those voltages, the electronic distributor some how appears to be set up correctly then when cranking advances the timing so the engine kicks back and turns over slowly. would it have done that with a temporary 12v supply straight to the coil + ? we'll never know now.

 

I would try one of the aftermarket electronic kits in it as that might shed some light on whats going on, as the electronic distributor kits are only a reproduced mechanical item with one of those trigger heads in it, now if it were to do the same again ..........................

[Captain Mainwaring]

 

 
We measured the volt drop on cranking.  With the new dizzy in place we got about 8 volts.  With the new dizzy,  in a retarded stance (or the old dizzy as per normal timing) it was 10.3v.   The mech enentually gave up and said he didn't know what to suggest. 
 

 
Thats the bit that doesn't make sense to me, he says with his old points dizzy correctly timed the voltage dropped to 10.3v   that sounds to be a normal sort of voltage drop when cranking.
 
With the powerspark fitted it drops to 8v, but goes upto 10.3 if they retard it so much it won't start...
 

 
Well we do know that the distributor can't be drawing so much juice that it's causing the voltage drop.....soooo, 
 
it's timing causing that - the engine is so far advanced that it's almost trying to run in reverse - cranking current is going up through the roof. Sooooo.....
 
Either the OP is getting the static timing miles out...or the static timing is changing.......
 
Now if the distributor was firing on the rising edge of the square wave instead of the falling edge, this would retard the timing....now we know that cranking voltage won't be stable - the OP's meter won't be quick enough to show the changes, but as each cylinder reaches compression there will be  voltage drop and over TDC the voltage will rise a bit before the next piston starts on compression.
 
You've got an OP who expects that if his car runs with his old system that when he installs a new system it must surely run better, and an ignition system that is naively documented and designed and doesn't state minimum voltage for operation.
 
Sounds like the OP has got bored with the whole thing - but if he was to stick a dedicated 12V supply on the distributor then the problem would be revealed.
 
It's all very well supplying what should be really simple electronics for making sparks but if every system condition and limitation isn't consider then problems like this can occur. 
 People who know what they are doing when they design control systems use a normally closed switch for tank level detection, those who copy are work don't...the difference? nothing until it goes wrong and either a detector fails or a wire breaks - our system generates an alarm, their system floods the place - same thing applies to copying electronics.

Edited by Captain Mainwaring, 02 July 2013 - 04:22 AM.