14 replies to this topic

[Haxeyman]

I  restored a 1989  998 a year ago installing two new looms (front and back) and rebuilding the engine as well as a new paint job and internal update.  I set everything up and when going, the car runs sweet as a nut.  The timing is set up OK, carb and mixture gives 35mpg.  However, I have now blown 4 condensers, each one lasting between 2 and six months, with the car doing about 500 miles per month, to and from work. It is a 10-15 minutes job to change the part (I keep one now in the car at all times), but when in a suit, in the pouring rail it is a pain.  I buy replacements (Lucas parts) from Motosave.  Have I just got a bad batch or is there something in the ignition set up I am missing which causes these failures.  Car is wired as a ballasted ignition with the correct coil.

 

Any ideas?

 

Haxeyman

[Ethel]

Perhaps the ballast wire's resistance isn't what it should be? I think I'd just upgrade to electronic.

[Captain Mainwaring]

Perhaps the ballast wire's resistance isn't what it should be? I think I'd just upgrade to electronic.

 

 

Wouldn't make any difference

 

To be more helpful, I can't think what you could do to a condensor to knacker it, short of stickin AC up it's kilt.

Edited by Captain Mainwaring, 27 July 2014 - 12:25 PM.

[Ethel]

Mmmm I suppose a capacitor can only draw what it can hold, but I did wonder if the higher voltage might generate a bit more heat in the internal connection?  Other dizzy manufacturers stuck 'em outside the case for better cooling. 

Overheating does tend to show up at the points though. 

[blackbelt1990]

I thought you had to change points and condensor at the same time otherwise they'd blow again?

[dklawson]

I thought you had to change points and condensor at the same time otherwise they'd blow again?

 

Not necessarily.  It's good practice to replace them together but the points are just a "switch" and the condenser is just a "capacitor".  While they are part of the same circuit, failure of one does not automatically mean failure of the other.

 

Regarding the ballast, there are a couple of possible problems that may be present in the wiring that will make for poor running but not necessarily failure.  If you have fitted a "standard" 12V (3 Ohm) coil to a car with ballast wiring, the spark will be weak and you may have marginal performance and a weak spark.  If your car has standard ignition system wiring and a ballast coil, current flow through the circuit will be excessive and the points, condenser, and coil all may fail prematurely.

 

Post back with specifics of your car's ignition system and we'll review whether your combination of components are matched.  Let us know what wires are on which coil terminals, paying particular attention to wire colors and that they may have faded.  If you have a multimeter, mark and remove the low-tension coil wires and measure the resistance across the coil terminals.  Let us know how many Ohms you measure.  

[woodley miniman]

Just read this thread....... 35 mpg, that's poor, I'm getting loads more, and mines a 998 too.

[jime17]

Just read this thread....... 35 mpg, that's poor, I'm getting loads more, and mines a 998 too.

That's all I get out of mine on my 9 mile each way urban commute. Id say that way par for the course.

[KernowCooper]

There is a influx of bad components about and even Bosch are being copied, to put a end to it I'd convert to electronic for less than £30 and be done with it, no more points/condensors and reliability.

[62S]

Get a new old stock condenser such as this one. Avoid the items in green Lucas boxes.

 

http://www.ebay.co.u...W-/281138220877

[dklawson]

With the exception of our Spitfire, my British cars have electronic ignition which does not use a condenser.  However, a few years back an acquaintance of mine got tired of dealing with condenser failures.  Being an electrical engineer he used industrial capacitors instead.  Please see the thread linked below for more information.

http://www.britishca...light=condenser

 

Succinctly, he bought industrial caps with the correct characteristics and attached leads to them.  They are then mounted outside the distributor (since they are not a traditional condenser shape).  One capacitor lead goes to earth, the other to coil (-)... just like the condenser that normally mounts under the dizzy cap. 

 

In a related thread, my friend started investigating the quality of condensers and why they were failing.  This is a long thread but worth a skim reading if you want an overview concerning the lack of quality in condensers.

http://www.britishca...light=condenser

[Haxeyman]

Folks

 

Thanks for all your replies and sorry for the late response.  I work away and have not been able to get to the forum since my first post.  

 

I have tried an electronic ignition, albeit a low cost one which replaces the points and condenser.  This lasted about 8 months before it too blew.  I have been buying the standard 'Lucas green box', but will try and now source something more original.  I also change the points at the same time as the condenser and there are no obvious signs of pitting or degradation when I do.  I have measured the voltage on the ballast wire statically and get 8.8V without load, which is where I believe it should be.  With the car running the voltage supplied to the coil is 9.2V again, well within the operating range of the condenser and so I don't believe there is a fault with the ballast resistance.

 

Looks like I just have some poor quality caps

[dklawson]

OK... so you know your car has a ballast ignition.  Are you running a ballast coil?  If not, the spark is going to be quite weak running a "standard" coil on ballast coil wiring.  Your coil and condenser issues may be non-issue if the right coil is fitted.

 

Regarding the electronic ignition, if you connected its red and black wires directly to the coil with the ballast wiring, it will not have been getting enough voltage.  You have to supply the module's red wire with a full 12V supply or the ignition system is likely to have problems.

[KernowCooper]

Thats maybe the reson your electronic kit died incorrect voltage