Classic car, (A35) ignition problem

[unravelled]

I'm looking for some ideas to help me sort out my car ignition. It is a fairly standard A series engine, and it seems to eat condensers. I have  a suspicion that it's simply because some modern condensers are rubbish, but I'm also looking for other possibilities. A basic electronic ignition is a last resort, but I do like to know what's causing a problem.

The problem shows up as a misfire/ lack of power, or even a reluctance to run at all. I am convinced it is a condenser problem, as replacing the condenser, and nothing else, cures the misfire, and restores normal running. The problem is that the last two condensers have failed after only a few dozen miles.

It is a 1098 engine, the only main alteration to the setup is an alternator.

 

I know that common wisdom says  swap points at the same time as the condenser, but I prefer to only change one thing at a time. Can badly set points, or wrong coil polarity kill condensers, (I think both are correct).

 

Any ideas?

 

Thanks

 

Dave

[Roddy Angus]

The condenser is just a capacitor so there is little that can go wrong with it. I would suggest you replace the points and make sure the gap is correctly set.

 

I hope that solves the problem.

 

Roddy

[stewartingram]

As a long term owner of an A30, which I basically "morphed" into an A35, I did about 250k miles in that car (on a shoestring!) Having done everything myself, I can't recall this particular problem Yes, points were cheap, easy to replace, though by todays standards a difficult job! I don't recall ever changing a condenser. Is the distributor moving ok? Are the plug gaps, leads and timing right? Does it start, using only one finger on the starting handle (though obviously you wouldn't normally need that). If set up right, that's how the A series should be in my experience.

 

Stewart

[polybear]

I'm looking for some ideas to help me sort out my car ignition. It is a fairly standard A series engine, and it seems to eat condensers. I have  a suspicion that it's simply because some modern condensers are rubbish, but I'm also looking for other possibilities. A basic electronic ignition is a last resort, but I do like to know what's causing a problem.

The problem shows up as a misfire/ lack of power, or even a reluctance to run at all. I am convinced it is a condenser problem, as replacing the condenser, and nothing else, cures the misfire, and restores normal running. The problem is that the last two condensers have failed after only a few dozen miles.

It is a 1098 engine, the only main alteration to the setup is an alternator.

 

I know that common wisdom says  swap points at the same time as the condenser, but I prefer to only change one thing at a time. Can badly set points, or wrong coil polarity kill condensers, (I think both are correct).

 

Any ideas?

 

Thanks

 

Dave

 

Change the coil maybe?

[russ p]

Is it the correct coil?

[unravelled]

Thanks for the comments. I can't say it has ever started with one finger on the starting handle, but when all was well it started easily enough on the handle. But all is not well. In originally troubleshooting this I changed all the electrical parts except the points, and as it is running OK since today's condenser change, I might well change them too. But three times in the last few months the problem has returned, and the last couple of times it has been cured by a replacement condenser, with no other changes. I have tried two coils, one standard and one "high power". There is no obvious difference between them at idling speeds. I tried exchanging them before replacing the condenser today, but with no effect. I did mistakenly order a ballast coil, which it ran with for a time, but it was replaced by something more standard a while back.

 

So I guess the immediate answer is to carry some spare condensers and allow plenty of recovery time on journeys...

 

Thanks

 

Dave

[PatB]

Whilst it's not condenser related, I once had an intermittent misfire on a Land Rover that was the very devil to trace. Turned out to be an almost invisible strand of copper from one of the LT lead spade connectors that would short to the distributor body. Short would occur. Misfire would happen. Pat would swear and fiddle, thus shifting invisible whisker. Engine would run fine again until copper whisker jiggled around to touch distributor again. Rinse and repeat. Only spotted it when it happened in the dark with the bonnet open and the engine running.

 

Also, don't dismiss an electronic set up as a last resort only. A basic unit which gets all the high current LT switching out of the dizzy and into reliable solid-state components can be built small enough to hide in a suitably 1950s looking box. Indeed it might even be possible to pack one, along with a compact modern coil, into the body of a dead Lucas or Runbaken coil. The original points will then only be switching mA and so will last forever with only minimal attention. Worth having in my book, and requiring no irreversible modifications to anything apart from, possibly, a dead coil.

Edited October 21, 2018 by PatB

[unravelled]

Thanks, the electronic igntion is only last resort in that I want to know whether there is any underlying problem which needs fixing.

The questions that this thread and my googling have raised, but not fully answered are:

Are some modern condensers rubbish, and if so how do I find a good one?

Is there an easy home test for a good condenser, so that I can throw out all the duds?

Can a faulty alternator, or anything else, cause the condenser to fail?

 

Currently, its thank goodness for a Freedom pass and Sainsbury's home delivery.

 

Thanks

 

Dave

[brigo]

A Google search came up with this rudimentary test using an analogue meter.

 

https://mgaguru.com/mgtech/ignition/ig129.htm

 

You can navigate his site using the arrows at the bottom of the page

 

Brian

[alastairq]

 Hi....First, I would contact the link below.

 

http://www.distributordoctor.com/

 

Over the past 20 years or so, many electrical components for car, once commonplace, but now only a specialised part, were made down to a specification [in China]....the belief, IMHO,the old cars with points ignition wouldn't be doing many miles a year anyway, so a set of points, [or a condenser] that lasted bt a year or so would be 'OK'..

 

The cost of parts made to 'original spec' making sundries like these a lot more costly.

Condensers do fail, largely due to vibrations and temperature, if not constructed in a manner which resists such forces.

 

My first thoughts on reading the OP, were, has the distributor earth been checked and re-done?.

 

Over time, distributors could have their earth connection [to the rest of the engine] compromised by oil, corrosion, etc.

 

Worth also contacting

 

https://simonbbc.com/

 

Replacing the CB points with a Hall effect system is quite cheap......and very effective. It doesn't rely upon magic black boxes or anything...simply either replacing the distributor baseplate with  the module already fitted [don't forget the insulating grease, very important].....or putting together a DIY kit from the above, does a couple of important things.

 

[1] it gets rid of the points, which can, and do, need adjusting at very regular & frequent intervals...especially if of modern manufacture[AKA, dubious actual quality].......

[2] eliminates the quite random ignition timing created by the mechanical bouncing around that points subject themselves to.....thus providing a consistent timing of ignition throughout the rev range....hence full advance can be confidently dialed in . Putting a strobe on the timing marks, and revving the engine to around 3-3500 rpm [to check full advance]..with points, may show the timing marks dodging around all over the place. A Hall Effect sensor will eliminate that altogether, hence full advance can be confidently adjusted.  

 

The Hall effect conversion merely changes the gubbins inside the distributor .......the coil is still used [but might do with an upgrade?]...but the condenser, etc, can be consigned to the bin.

 

[As an emergency , the baseplate, with points & condenser properly set up & adjusted, can be carried in the glove box, so if the modern electronic ignition should faile, simply replacing the base plate [a couple of screws, don't drop them inside ]....will restore things to original....until the condenser fails, that is......that is how simple the Hall Effect system [powerspark, for one?] is, to install & replace.

 

Distributor Doctor makes their own condensers, to original & upgraded spec....also worthwhile getting one of their red rotor arms.......[Chinese rotor arms,, usually black, were a case in point, as above...the Chinese factory used too much carbon in the plastic mix....so the rotor arms would short themselves out]......

 

Sadly for old car & bike owners, despite the advances in technology today offers.......today's economic and commercial pressures mean a drastic lowering of quality of minor , but essential, component specs.

 

Even bits advertised as 'new-old-stock' [NOS] cannot be trusted, as even boxes were 'cloned'.....

[unravelled]

Thanks, I had already flagged distributordoctor as a likely source of better quality spares, and I will probably buy there when I decide what I need. When I had electronic ignition in a previous A35, I kept a complete spare distributor in the boot,(A35's don't have the luxury of a glove box...) in case of failure. It was never needed.

So yes, I should really go pointsless. It's the logical thing to do, but it will niggle if i don't get to the bottom of this issue.

 

Dave

[kernowtim]

Has this been fitted with a ballasted ignition coil by any chance, designed to run on 9v supply, used without the ballast resistor?

Were common on ford's from memory!!

[alastairq]

Thanks, I had already flagged distributordoctor as a likely source of better quality spares, and I will probably buy there when I decide what I need. When I had electronic ignition in a previous A35, I kept a complete spare distributor in the boot,(A35's don't have the luxury of a glove box...) in case of failure. It was never needed.

So yes, I should really go pointsless. It's the logical thing to do, but it will niggle if i don't get to the bottom of this issue.

 

Dave

 

With the Hall effect [sparkright type] ignition module, the base plate only is replaced [by Distributor Doctor....Sparkright simply sell the components for the owner to fit, hence my reminder of the grease?]....All the thing consists of, is a sensor block which is screwed to the distributor base plate,  [with grease underneath it]....and a magnetic ring, which slots over the distributor cam area, underneath the rotor arm.....plus, two wires leading out from distributor to coil.

 

Rather than keeping an entire distributor in the boot..[which needs to be timed up on fitting, as no two dizzies are exactly the same]....probably better to simply get a spare base plate, kit it out with points & condenser....setup in a dizzy for gaps, etc....then, if ignition does fail, simply unscrew baseplate, and swap over[ don't forget vacuum advance circlip]....the timing of the ignition will be retained.

[doilum]

Has this been fitted with a ballasted ignition coil by any chance, designed to run on 9v supply, used without the ballast resistor?

Were common on ford's from memory!!

Beat me to it. Back in the day I had an RS2000 that defied the combined knowledge of some very able friends and mechanics. By chance, I needed some MOT welding and my usual mechanic was out of the country with a works rally team. I happened to mention the ignition problem to the welder who fixed it in half an hour. Seems that the ballast resistor was integral in the loom, possibly behind the dash. He rigged up an external one on the inner wing. Job done.

Having run an MGB as an everyday car for over six years my first advice would be to invest in a new dizzy and electronic ignition asap. With a correct spark even the most worn motor will start and perform.

[unravelled]

Thanks for all the comments and advice. I have now decided to see sense and have ordered a pointsless replacement. Once I've made sure that the leads and coil are right for it, I'll get it installed, and report back.

 

Fingers crossed...

 

Dave

[stewartingram]

I assume you are a member of the Owners Club? Also have googled spares from specialists? And, really teaching you to suck eggs, (sorry), are aware of the vast range of BMC cars that used the same spares?

 

Stewart

[Dunsignalling]

Back in the seventies, I spent a while being frustrated by a random misfire on my Dad's beloved 1961 Hillman Minx, which had become the family "common user" when he got a company car. 

 

The eventual solution, found after over an hour spent on a kind person's driveway outside Bridport when it got so bad it wouldn't do the modest hill, turned out to be the points.

 

The reason it had gone undiagnosed previously was that one of the contacts, which are fitted into the spring steel like a rivet, had worked slightly loose. Of course, as soon as a feeler gauge was inserted, everything looked perfect. It was only when it worked loose enough to cause actual failure, and the dishonour of having to arrive home by bus loomed, that our concentration became sufficiently focussed to find the cause.

 

BTW, my brother is a trained car mechanic and he'd also been mystified for weeks. To be fair, though, it was him who eventually spotted it.

 

Every car I bought thereafter got an electronic conversion kit asap.

 

John

Edited October 21, 2018 by Dunsignalling

[unravelled]

I assume you are a member of the Owners Club? Also have googled spares from specialists? And, really teaching you to suck eggs, (sorry), are aware of the vast range of BMC cars that used the same spares?

 

Stewart

New methods of egg sucking are constantly being invented, and it's sensible to keep up with alternatives. I've been in the owners club for over 40 years now(!), but haven't attended a rally for a good few years. Mine is an everyday Austin and needs to get there under its own steam. Maybe if I can sort the reliability I'll get to one next year.

The  vans I've had over the years have had parts from various cousins incorporated. I had a late (1968) van which was a bit underpowered with its 848 engine. It ended up with a Sprite 1098 engine (with Oselli prepared head), Sprite front disk brakes and hydraulic rears. Sprite halfshafts were a necessity with an appropriate diff, although this meant I had to renumber the speedo, (using tippex  if I remember correctly). The engine rebuild was done in my bedsit, and the work done in the street.

There are lots of fun problems swapping parts of different makes/ages. Morris minor 1098 engines don't have a hole for a mechanical  fuel pump, so electric is required. The sprite block had a fuel pump hole, but no drive lobe on the cam. Early cars had diffs with a filler, later ones had the filler on the casing, so you can end up with two fillers or none. Guess which combination I ended up with a year back...

 

My latest mix and match has been to adapt minor front brakes to fit.

 

It's all fun...

 

Thanks

 

Dave

[alastairq]

Even more fun when one factors-in stuff off the Marina range? {Don't use the Marina gearbox...it's aTrumpet-based lump of old cast iron, your sills will sag with the weight]

[russ p]

Swapping A series stuff is fun except when it involves scrapping metro turbos ( especially mk1) to yield power units !

[PatB]

If I remember magazine articles on A-Series tuning correctly, there were several dozen distributor variants across the range, with multifarious advance curves, vac and no vac, taco drives or not, and several points designs. Whilst they'd all physically fit in the 'ole in the side of the engine, and work after a fashion, they wouldn't necessarily work well.

[russ p]

There were also a number of different drives from the cam to the distributor

[Yardman]

It looks to me like a coil with shorted turns (or the wrong coil), causing excessive voltage to the points and Condenser. Try a different coil.

I would go for contactless electronic ignition, much more reliable and nothing to wear or adjust.

[TrevorP1]

One random thought. Is the distributor baseplate earth lead in good condition?

 

For what it's worth I've run a TR3a for the best part of 25 years and have stuck to the original ignition set up. At one point I was using the car regularly on the continent and was happy to know that with a 'pocketful' of bits I could repair the ignition system anywhere. My concession to modernity is to use Iridium spark plugs, they are well worth the extra cost and genuinely give smoother running and better fuel economy.

 

Through bitter experience I avoid parts from China like they carry the worst kind of plague imaginable. I've found Martin Jay at Distributor Doctor to be the 'go to' man for top quality ignition spares. His delivery times are nothing short of excellent, often less than 24 hours.

[2mmMark]

My Royal Enfield Bullet has points ignition with an inductive discharge electronic box in circuit. This obviates the need for the condenser and just uses the points as the spark trigger. You can keep the condenser in place but simply disconnect it.

 

The Boyer box I use has a little light to indicate the points opening so setting the timing is a doddle.

http://www.boyerbransden.com/IDunits.html

 

I've had a pair of ID units on my Laverda SF3 since 1982. The Bosch points it uses are now pretty much unobtainable and the unit prolongs their life hugely.

 

Contactless electronic ignitions often require a minimum voltage in the system so won't respond to a push start if the battery ever goes flat. The ID box is much less sensitve in that situation.

 

Mark