A series 1275 starting problem

[Chris Roden]

Our 1275cc Mini will only fire when the ignition key is released from the "cranking" position i.e. Ignition on. Obviously this makes it very difficult to start as you have to guess the correct time to release the key for it to fire.

My assumption was/is that there was insufficient power to provide a good spark while the starter motor was being turned.

The ignition system is standard, distributor, non ballast resistor coil, points etc. and everything is in good condition/new and a new battery is fitted. Timing, points gap etc. are all, as near as possible, correct.

Going over the car today, I discovered that the voltage at the + terminal of the coil is only 9v with the points closed, but jumps to 12+ volts with the points open. Is this correct and if not, where is the problem likely to be?

Any suggestions gratefully accepted.

[GORDON STREETER]

Will it start if you juice the + Side of the coil up directly ? and are the two low tension wires on the right way round ? it will run either way but wont start easily and make sure it hasn't got a resistor in line as you are only getting 9v
If it does start by juicing it up then you have a dodgy ignition switch or connection somewhere, also make sure that the fuel hasn't "gone off" if it's been sitting about.
These are one of the easiest cars to work on so it should be easy.
Have you done anything to it before the problem ?

[GORDON STREETER]

Reading your thread again you stated "everything is new/good condition" have you fitted a new coil ? if you still have the old one stick an ohm meter between the LT terminals, if it reads 1 to 2 "ish" then it's a ballast coil, a non ballast one will read 3 to 4 "ish, an electronic one is almost a direct short !
Oh and the points should be closed when testing to see if it has a resistor !!! it looks like you have !

[Chris Roden]

Thanks Gordon

Connecting a battery between the + terminal on the coil and earth doesnt seem to make any difference.

I'm a bit confused about your reference to the LT leads being the wrong way round (I'm a bit dim!). The ignition switch lead is on the +ve terminal, the -ve terminal has a feed to the points and another to the rev counter. There are no other leads to the coil (other than HT of course).

The coil is now back to the original, I had swapped it for a known good alternative but that didn't do any good. I don't have a suitable meter to measure Ohms so I can't test the coil at the moment but I will rectify that omission at the weekend...

The thing that really confuses me is that, with the points closed, the voltage at the + terminal (ignition on) is 9 volts, cranking drops that to about 7 volts, however if I remove the wire from the +ve terminal of the coil and take the voltage reading from the end of the wire it's 12+ volts. Why should there be a voltage drop simply by hooking the lucar back on to the coil terminal?

I did wonder if I had a ballast resistor but, if that was the case, I would have expected two wires to the +ve terminal, the ballasted one for normal running and a bypass for starting. Also if I had a ballast resistor shouldn't I expect to see an increase in voltage when cranking rather than a drop?

Fuel was new on Tuesday....

Finally, with the feed from the ignition switch disconnected from the coil end, as mentioned, I am getting 12+ volts so does that not suggest that the ignition switch is Ok?

Thanks again for the help

Perplexed

[GORDON STREETER]

No no no, I said juice it up ! meaning put a positive to the + side of the coil !!
it should start then even if you have a ballast coil but of course it wont run forever because it will burn the points and coil out eventually.
Lots of Mini's had a resistor wire from the ignition switch to the coil and the 12v start voltage comes from a separate terminal on the starter solenoid.
Of course I cant see from my house what the problem is but if you are only getting 9v at the coil with the points closed then it looks like there is a resistor wire or a dodgy terminal somewhere.
Just do what I've said and run a wire to the positive terminal on the coil to a 12v feed from the starter solenoid where the main loom pick up is attached.
Temporarily disconnect the rev counter if it has one on the coil
You will get a 12v reading from the ignition switch wire because there is no resistance if it's not connected!

[Chris Roden]

Originally Posted by GORDON STREETER

No no no, I said juice it up ! meaning put a positive to the + side of the coil !!
it should start then even if you have a ballast coil but of course it wont run forever because it will burn the points and coil out eventually.
Lots of Mini's had a resistor wire from the ignition switch to the coil and the 12v start voltage comes from a separate terminal on the starter solenoid.
Of course I cant see from my house what the problem is but if you are only getting 9v at the coil with the points closed then it looks like there is a resistor wire or a dodgy terminal somewhere.
Just do what I've said and run a wire to the positive terminal on the coil to a 12v feed from the starter solenoid where the main loom pick up is attached.
Temporarily disconnect the rev counter if it has one on the coil
You will get a 12v reading from the ignition switch wire because there is no resistance if it's not connected!

Thanks Gordon, I'll try that tomorrow....

[GORDON STREETER]

Just a thought, you said that you can only "get it to fire" do you mean that you have actually had the engine running ?

[Chris Roden]

Gordon
Yes, if you can pick the exact moment to release the key from cranking the engine it will start and run ok. When it is stone cold, this is very difficult and I have had to resort to the old trick of warming the plugs in an oven then I can just about get it to catch.

'er indoors has done the Sainsbury's run in it today but it took me about half an hour to get it started from cold.

Once the thing is warm, it will start easily but again, only once you release the key from the cranking position. I assumed that this was because the timing of the key release was less critical because the engine was warm.

It was this behaviour that led me to believe that the problem was in the ignition switch itself. My conclusion, rightly or wrongly, was that the coil was being robbed of voltage when the key was in the cranking position. It was this that took me down the road of measuring the voltages at the coil +ve terminal where, perhaps stupidly, I expected to see 12volts.

In fact, as mentioned, I saw 9 volts with ignition on and points closed, 12 volts with ignition on and points open, and 7 to 7.5 volts cranking.

Just to throw in a couple more red herrings, the loom has clearly been "heavily modified" (buggered about with!) by previous owners.

I have the relevant Haynes manual but despite comparing the wiring with all of the various years & models wiring diagrams in the book I can't find a match. According to Haynes I should have a white lead (non ballast resistor) or a white/yellow & white/pink (ballast resistor) to the coil +ve terminal. I have a single red wire.

I wonder if, longer term, I should consider a new loom.

Also, the the solenoid is the good old fashioned type with a starter button between the two terminals. It doesn't make any difference whether I use the key or the solenoid button, coil +ve voltages are the same. I assumed that this was another indication that the Ignition switch was OK.

According to Haynes, apart from the main battery & starter motor feeds I should have a white/red (Alternator), 2 browns (fuse box & ignition switch) and a brown/blue (Alternator) connected to the solenoid. I only have 2 browns and so far I have failed to establish where they go. They disappear into the loom tape so I can't follow them by sight and testing continuity is inconclusive/confusing.

I should never have succumbed to 'er indoors desire to relive her youth by buying her a mini I should be working on the racers.

Thanks for reading these ramblings and offering help.

[GORDON STREETER]

Come on spark the coil up and get it going

[sebring115]

Have you also checked its not an earth problem. Sounds like you get a voltage drop when the starter is cranking.

To check this use a jump lead from the engine to the battery (which could be a problem as its in the boot!) In fact have you cleaned the engine and battery earth points??

If you cant get a jump lead long enough you could always put the battery by the engine bay and then a live jump ;lead to the solenoid and the earth onto an engine stud.

Goof luck!

[Chris Roden]

Originally Posted by sebring115

Have you also checked its not an earth problem. Sounds like you get a voltage drop when the starter is cranking.

To check this use a jump lead from the engine to the battery (which could be a problem as its in the boot!) In fact have you cleaned the engine and battery earth points??

If you cant get a jump lead long enough you could always put the battery by the engine bay and then a live jump ;lead to the solenoid and the earth onto an engine stud.

Goof luck!

Sebring
Thanks for your suggestions.
I've cleaned up all earth connections, tried a jump lead between a head stud and a known good earth point on the shell and I've also regularly used a jump start battery between the solenoid and a head stud.

Fortunately, some years ago I bought a set of heavy duty jump leads in Kuwaitm, lo and behold, using a combination of the red & black leads, they will reach from the block to the battery in the boot so I tried your suggestion this morning but it made no difference.

Thanks again...

[Dave Brand]

Originally Posted by Chris Roden

Also, the the solenoid is the good old fashioned type with a starter button between the two terminals. It doesn't make any difference whether I use the key or the solenoid button, coil +ve voltages are the same. I assumed that this was another indication that the Ignition switch was OK.

Have you tried starting using the button on the solenoid? That would give an indication as to whether or not it's an ignition switch fault.

[Chris Roden]

Originally Posted by GORDON STREETER

Come on spark the coil up and get it going

Done....

Engine started with no problem.

Made up a temporary cable and connected solenoid to coil having removed the original cable and disconnected the Tach feed.

With the temporary lead in place I have 12volts at the coil +ve terminal and as I said the engine starts fine. I ran the engine like this for five or ten minutes and the coil didn't seem to get warm but I don't suppose that proves much.

(had a minor panic, until the penny dropped, when I turned off the ignition and the engine kept running)

I guess the (simplest) next steps are:

Check whether the coil is ballast/non ballast

If non ballast run a new lead to the coil and abandon the original.

If the coil is a ballast resistor type, swap it for a non ballast type and run a new lead as above.

or is there a better way?

Thanks again Gordon, at last I feel as though I'm getting somewhere.

[GORDON STREETER]

Thank God for that !
As it looks like you have a resistor in line i would use a balast coil and run a lead from the solenoid to the pos on the coil as well as the resistor lead.
What you may not have is the correct solenoid as it has got to have the correct take off for the 12v start.

[GORDON STREETER]

This is the solenoid you want, note the other terminal for the 12v start circuit. If you are going to use the balast system this is the only easy way to go
http://www.ebay.co.uk/itm/MINI-MK3-4...id=p4340.l3484

[GORDON STREETER]

Oh, and don't just think that you can just take a feed to the coil from the starter side of your solenoid as it will try to work the starter from the coil when the ignition is switched on and burn the wire out !
Sorry to rant on but it doesn't seem that car electrics are your main job

[Chris Roden]

Originally Posted by GORDON STREETER

Oh, and don't just think that you can just take a feed to the coil from the starter side of your solenoid as it will try to work the starter from the coil when the ignition is switched on and burn the wire out !
Sorry to rant on but it doesn't seem that car electrics are your main job

Tried that!

It didn't burn the wire but the car wouldn't carry on running once the ignition key was released from the cranking position.

Please feel free to rant on, you seem to know what you're talking about

...and no, car electrics, in fact car anything, is not my main job, merely a hobby

[dulon]

Had the exact same problem with my road going mini, its a worn ignition, i just replaced the ignition barrel complete, not expensive and ensured it was a little harder to steal.
A local guy had recommended that i went to the older form of ignition with the key in the middle of the dash and use a button on the floor or get a horn button, but i wanted to keep the ignition lock as a deterent.

Hope you get yours sorted ok, and as yours runs ok once its started the same as mine, it sounds like a similar thing.

[Chris Roden]

Oh, and as the law of sod dictates, I've got three good spare solenoids sitting on the shelf and not one has the extra terminal needed.

[GORDON STREETER]

0f course you can do away with the ballast system and run a wire from the ign switch to a 12v coil and it will work ok as that's all they had for years.
However the ballast system will make it start easier especially if the car isn't used much, also the points will last a bit longer.
All this is old hat and easy to sort out compared with modern cars with cambus wiring, I had a customer that fitted a wrong bulb in his Volvo that stopped it going and cost him a new ECU at several hundred pounds, so a little knowledge can be a bad thing !

[Angus Theape]

haven't read every post in this thread, so apologies if this is a repat. Check the ignition is not wired to the auxiliary position for the radio as that disconnects the power to the ignition when the starter is operated. When you get the thing to spun fast enough, usually when its hot after a tow start, it will fire off the key as it is still turning when the ignition is restored on releasing the key.

[GORDON STREETER]

Originally Posted by Angus Theape

haven't read every post in this thread, so apologies if this is a repat. Check the ignition is not wired to the auxiliary position for the radio as that disconnects the power to the ignition when the starter is operated. .

It's all sorted, as you said you haven't read every post

Post 8
"I saw 9 volts with ignition on and points closed, 12 volts with ignition on and points open, and 7 to 7.5 volts cranking"

[Chris Roden]

Update:
I've fitted a temporary switch, position 1 connects battery direct to coil (via solenoid) for easy cold starting, position 2 connects ignition to coil for normal running.
The routine is, switch in position 1, start engine, move switch to position 2, easy.

New solenoid is on order and should be delivered Friday/Saturday so I'll report back when it's fitted.

Thanks again Gordon, much appreciated, price of a pint or two of Larkins on its way to your P.O. Box.

[GORDON STREETER]

Originally Posted by Chris Roden

Thanks again Gordon, much appreciated, price of a pint or two of Larkins on its way to your P.O. Box.

I must have a look in that PO box as there must be millions of pounds in it by now, that's if I haven't been scammed !
Are you running it with a 12 or 9v coil at the moment ?

[Chris Roden]

Originally Posted by GORDON STREETER

I must have a look in that PO box as there must be millions of pounds in it by now, that's if I haven't been scammed !
Are you running it with a 12 or 9v coil at the moment ?

The 9v that has been in there all along.

'er indoors had a hospital appoinment at the crack of dawn this morning. Mini started perfectly using the new temporary switch arrangement......

She parked in the hospital car park and, when she retured to the car, 5 hours later, the engine wouldn't even turn over. Panic ensued, followed by frantic phone calls to me.

A quick trip up there, armed with tools, coils of wire, jump leads, tow rope etc. etc. 5 seconds diagnosis, and I had found the fault. If she had turned the headlights off when she parked the car the battery might not be quite so flat.

Happy days!

The trouble is that the other road cars have these new fangled automatic headlights that switch on when the light is low and switch off when ignition is off. Looks like she/ we will have to re-learn old habits if we're going to use a 40 year old Mini.