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MG Midget and Sprite Technical - Coil Problems

Hi, new to the forum and I am hoping someone might be able to help. My poor midget is back in the lock up in disgrace...again. Bought her 5 years ago. Sorted out lots of problems and she has gone fine for the last two Summers, but this Summer its been nothing but problems. It started with the coil burning out. She was going fine then just lost power and stopped. She would start again after a few minutes, run for a few minutes and then stop again. We had to get uplifted and took her to the chap who has been looking after her for us. He specialises in old cars and racers so knows his stuff. He fitted a new coil and checked her over. She went fine for a little while. We havent had the chance to take her on any long runs this season so trips out would be maybe 40-50 miles with probably a stop for coffee. Then she did it again. Just cut out. After a while started again, this time she ran long enough to get her home. Took her back to the garage and had all new leads and distributer cap fitted. She ran well...sounded good....so thought that was it solved. But Sunday took her for a run as it was such a lovely day. Did about 35 miles...she gave a little cough....and 5 minutes later she stopped. It was in a really dangerous place on a blind hill with no verges to get her off the road so we were a little concerned we were going to cause an accident. She started just enough to turn her round and coast back down the hill out of danger....but that was it. Another uplift back to the lock up. Have totally lost confidence in taking her out. If we cant sort it then my husband says she has to go. Please can anyone help save the day as I love my little car.
L Scobie

Hi, and welcome to the friendly BBS!
If your mechanic is experienced then he should have found any normal faults. What he may have missed though would be an abnormal fault specific to the model. The syptoms as described could be a number of things but one distinct possibility is a faulty rotor arm inside the distributor. There are bad ones around that work fine for a while and then give up, especially when warm. When they cool down again they work properly. For this reason it is a fault which rarely shows up when the car is being checked and tested in the garage - it needs to run for a while under road conditions for the fault to occur. The solution is simple - get a new RED rotor arm from:
http://www.distributordoctor.com/red-rotor-arms.html
Guy W

Can you provide a little more information? What year is the Midget and what engine?

Rob
Rob aka MG Moneypit

Its a rubber bumper car...
Theres a picture on the MGEXP site.....
Andy Phillips (frankenfrog)

What Guy said!
Had exactly the same symptoms as yours and cured completely by replacing with a Red rotor arm.
Some of the cheap black ones have a rivet on the top which works fine for a while but then starts to short out and cause the peoblems you're encountering.
Jeremy Tickle

Hello and welcome.

x3 on Guy and Jeremy's comments.
Don't ask how I know......
Greybeard

Similar problems in April this year but I had a new old stock lucas rotor arm and not a nasty modern reproduction. Turned out it was the condenser although this was a nos item too! I gather they can fail over time. A new condenser from the Doctor solved it. 2000 miles later and all is very well!
Bob Beaumont

Had these exact symptoms on my TF. Took me ages to find the cause.
After replacing coils, condensers, plug wires, rotor arms, turned out it was a needle valve in the front float bowl intermittently sticking shut. It wasn't leaking and the valve was moving freely up and down until it seemed as if it suddenly got glued to the seat.
I'm blaming ethanol. And I have a another phrase to counteract 'most fuel problems are electrical'. If it seems like a fuel problem, it probably is.

David
David Wardell

Linda,
A fine looking car (apart from the colour ;0)
As you will see from the posts above (all reasonable suggestions BTW), there are lots of possible causes but there will only be one solution! The problem is finding the one cause and one solution when the car works fine in the garage! Ideally your mechanic should be on hand to see exactly what is going on when the car fails; otherwise it's just guess work.
Get in touch via email where we can try and arrange for your next run out to be close to me when it fails.

Best of....
MGmike
M McAndrew

OPPS... THE CAR IS A 1500 midget

Not a 1275

Andy Phillips called... spot on!

Linda... NICE CAR!!! My thought is husbands are much easier to replace then great cars like yours... im single and avialable...haha

Linda

Do you know if the ignition (distributor) is orginal or has it been replaced with an aftermarket upgrade ???

Here is Lindas link on the MG experiance web site

http://www.mgexp.com/phorum/read.php?3,3110066

Prop
Prop and the Blackhole Midget

Nnn....
Prop and the Blackhole Midget

A photo of Linda s very NICE 1500 midget

So whats the consensus...

should linda keep the husband or keep the car ?

apperantly one of them has got to go when the car is sorted

Prop
Prop and the Blackhole Midget

Ttt.
Prop and the Blackhole Midget

Prop,
Easy choice I think :0)
If chosen correctly Husband V2.0 would be a much better place to spend any upgrade money. Hee Hee.

Best of...
MGmike
M McAndrew

1500 or 1275 - does it matter?
Moss sell a cheap rotor arm with a rivet (1.80) as well as a 'high quality' red one (6.25) for the 1500 engined Midget so surely the same issues can arise?
http://www.moss-europe.co.uk/shop-by-model/mg/midget/electrical/ignition-system/distributors-1275-1500cc.html
Jeremy Tickle

Mike

Thats my thinking also husband 2.0 haha... I know linda is sight unseen, but if she is driving such a cool car and SHE is tracking down the problem, she is definatly an awsome keeper in my book : - )

Prop
Prop and the Blackhole Midget

1500 or 1275 - does it matter?

Jeremy,

Im not sure to be honest.

On the 1275, the red rotor bug go to should be considard standard procedure and is for the most part

But for the 1500, the factory stock dissy is completely differant then the dissy for the 1275

But aftermarket dissys are the same for both 1275 and 1500

Plus add that, its alot more common for owners 1500s to change out the factory dissy for an aftermarket upgrade dissy because of there Cei weeknesses

Id say her issues are going to be (...) if it is a dissy problem

1. If its stock ... im going to take a wide round house flaing kick attempt so back up, but that fuse link thats built into dissy wiring it may be worn / aged. Im wondering with 40 years on the clock, engine heat and x000s of miles of engine vibration, that t fuse link might be on its last leg

2. If she has an aftermarket mallory 27 series then I know for an absolute fact that its the mallory condensor as installers almost never sand the finish/coating off the condensor, and it slowely looses ground and acts the like linda discribes

3. If its a pretonix dissy then from my personal experiance ... the dissy computer chil is what peter burguss described to me a phazing , where the chil is actually loosing time and advances the timming causing alot of over heating of the coil... BUT pertronixis an american part and not very common in the UK, as the more common HALL (pertronix) ignition system in the uk is the ("simion ???" ) and im not aware of the (simion ) phazing, or heard of it

The good news is ... the likely hood that my new wife to be (linda) :-) probably dosnt have points and condensor to deal with... the bad news is linda probably dosnt have the simplicity of points and condensor and has some type of electronic ignition system. Lose /lose

Prop
Prop and the Blackhole Midget

Hmmm I forgot to post a pic of linda car

Prop and the Blackhole Midget

Linda..

Don't panic!

Prop's a great guy but he - er- hears another drum now and then!

Rotor and condenser. It seems the consensus is pointing that way. The good news is that they are both inexpensive items to try, but take care to get good quality parts. The distributordoctor website can help.

As a guide, back in the day my Dad taught me to replace the condenser, points and rotor all at the same time for peace of mind. You've already done the the HT leads and cap so they should be okay if they were good quality bits to start with.

It sounds like you have an ignition problem rather than fuel to me and the things suggested are easy and cheap to do, so I think they're a good start. Eliminate those first before looking for complicated stuff would be my suggestion.

Great looking car by the way. I'm a Midget heretic in that I like 1500s (like mine).

Good luck, don't forget to tell us what happens please.

Cheers;

Rod.
Greybeard

There could be a number of faults. But the key bit of information to me was that the car had been checked by someone who "specialises in old cars and racers so knows his stuff". I would therefore assume that he would pick up on condenser, blocked fuel jet, faulty HT lead etc all as typical normal "old car" culprits. But he just might not be aware of the faulty rotor arms in circulation. And the way these fail does fit the described intermittent nature of the fault. I could turn out to be way off the mark though!
Guy W

"And the way these fail does fit the described intermittent nature of the fault." It does, to a tee. For 6 it's where I'd start.
Jeremy Tickle

....... particularly the way it runs again when it cools down. It's the heat which can upset the rubbishy rotor arms.
Graeme W

Btw... just a heads up, the stock 1500 dissy is an electronic ignition system so it wont have points and condensors

2nd...I can not recall the rotor bug in the factory orginal 1500 dissy being an issue ... but then agian,ive never paid much attention to 1500 issues

I do know the stock dissys for the 1275 and the 1500 are completely differant from each other... so id think the rotor bugs are differant as well

Am I wrong on this

Prop
.

Prop and the Blackhole Midget

Prop, UK cars used the non electronic version of the Lucas 45D4 dizzy. It has points. I think it was the same unit fitted to the later 1275 Midgets. Its certainly very similar.
Guy W

Ahhh ... Thanks guy, I did not know that.

In the usa the 1275 never came with electronic but when the 1500 began in 75, that was the 1st midget to come with electronic here in the usa

Now this thread makes scence... I coundnt figure out why I was the smartest bloke in the room knowing the 1500 only came in electronic ignition...HAHAHA

PROP...in my kingdom I dont own cloths
Prop and the Blackhole Midget

Overwhelmed by the response...thank you all so much. Giving hubby a list of things to check and think I will give him a second chance as I've only had him three weeks...lol.
L Scobie

Linda,
the thing with the faulty rotor arms is that they cannot effectively be checked. The only practical solution is to buy one of the quality red replacement ones and swap the part. They are not expensive and it doesn't require any adjustment or tinkering - you just unclip the dizzy cap, pull the old rotor arm off and press the new one on in its place. Even then you won't really know if it is cured until you go for the same sort of distances that caused the breakdown before. And the further you travel the more your confidence will increase. Unless of course it breaks down again and then its back to square one for fault finding!

Good luck!
Guy W

Linda wrote on the experiance site

Thanks for all the feedback. She had a new distributer and new leads fitted after her last hissy fit so will work our way through all the other suggestions. We also had an electronic ignition fitted when we first bought her and there is a suggestion that it may be too powerful and is causing an overload to the coil, so she is going in to the garage tomorrow to have this taken out and a "Petronix" ignition put in. Guess its just a matter of eliminating things one by one. Once again thanks for all your advice.

Prop and the Blackhole Midget

Linda...

Id stay points and condensor till is sorted

Id also go with the simion chip... its local for you, less expensive, and better quality then the pertronix chip

Both are HALL systems

Prop
Prop and the Blackhole Midget

http://www.simonbbc.com/

Prop
Prop and the Blackhole Midget

Good advice Prop about the Simonbbc unit. But it still uses a rotor arm presumably. My MG metro adapted electronic system still does.
Guy W

Yes the Simonbbc ones still need a rotor arm, but you can buy a bundle with the unit and a rotor arm (red) or one with both and a cap. That is what I did and very pleased with it.

Trev
Trevor Mason

"Less expensive and better quality than the Pertronix chip".
Less expensive, yes, but my Pertronix ignition has done about 9,000 miles of cruising, being thrashed, and pottering around and has never missed a beat. Starts first time every time and I get great MPG.
Bernie Higginson

Bernie, all of that applies equally to the Simonbbc ones. Not sure how long I have had mine or how many miles it has done without checking ut it has proved very dependable.

Trev
Trevor Mason

From recent experiences, I would think this is likely to be a condenser fault. However, I would agree it could equally be the rotor arm, so if ordering a red rotor arm from the Distributor Doctor, I would suggest getting a new condenser from him at the same time.

Hopefully that will cure your woes at modest cost so you can keep the car.
Peter Blockley

All, an electronic ignition unit doesn't use a condenser! Now that's eliminated it could still be the rotor arm but I would expect a new one in a new dizzy, so possibly not the problem.
I agree the fitting of the pertronix is a bit of overkill at this stage but hay ho it will eliminate that part of the equation.
I still say working on it in a failed state is the only way to be sure or you are trusting to luck (and cost). I'd much rather pay 100 for someone to drive it around until it fails than x00's on new parts with no progress. I'm available :0)

Best of....
MGmike
M McAndrew

Mike, I don't think it has had a new dizzy, just a new dizzy cap and plug leads. Given the low cost of a rotor arm I would have fitted a new one anyway, but maybe he didn't do so.
Guy W

Guy

It is confusing to read, on one hand she says a new dissy was fitted, but rhen right after that she mentions they installed new cap and leeds then installed the old electronic ignition they they got whey they 1st got the car

It also sounds like they mating a ballasted with a non balasted system and causing the coil problem.

If thats the case they dont need a new igntion chip they just need a ballast

I question the ability of the mechanic, I have a gut feel the shop owner is competent but perhaps this car is training work for a flunky


Linda says ....

"""""She had a new distributer and new leads fitted after her last hissy fit so will work our way through all the other suggestions. We also had an electronic ignition fitted when we first bought her and there is a suggestion that it may be too powerful and is causing an overload to the coil,
Prop and the Blackhole Midget

Pertrinox vs simionbbc

Its just my opinion .. ive had 3 petronix chips... all failed

The 1st because I accidental shorted it out while working on the car, 2nd shorted out because the red and black wires are really cheap and the insulation broke down at the chip because it was "hinging" everytime the dissy advanced, the 3rd started " phazining" which throws off the timing really bad... so ive gone back to P&C.

Having seen the simion bbc chip, i think it just looks the part

I only recommened that linda temporary go back to P&C to get this fixed then convert to the chip, because it dosnt take alot of juice to open a sealed pertronix chip and let the blue magic smoke out and these chips aint cheap... with cost, tax and shipping about $140.00 usa on avg. So better to risk a $10.00 points set then a chip when your diagnosing the unknown problem

Prop

Prop and the Blackhole Midget

Sorry Prop, I didn't see that bit about a "hissy fit" and replaced dizzy. I thought it was just the cap and leads as mentioned in Linda's first post.
Guy W

No apologies needed here... im just as confused as you are

Im still lost as to why they got the new dissy, then used the old eletronic ignition and age going to replace it with a new chip instead of just installing a ballast resistor for $2.49 and 5 minutes of time

.... and a red rotor

Another thought considering its a new dissy i wonder if its set over advanced


Prop
Prop and the Blackhole Midget

This thread was discussed between 21/10/2015 and 25/10/2015

MG Midget and Sprite Technical index

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