Distributor Question

[Oggi]

My Herald has started playing up again. It was starting fine idled well and reved fine. I left it on the drive ticking over to get it warm and all was well. Turned it off went to put it back in the garage and nothing absolutely no spark.

So far I have a strong pulse from the coil, another new set of Lucas points, condensor and rotor arm, still nothing. I have tried with an inline spark tester and this is where it gets weird, most of the time no spark and then every now and then it will give an odd spark and try to run, the spark is then frequent for about 2 seconds then dies again. Is this the distributor or control box. The cap leads and plugs are newish I have also tried two other caps and sets of leads, I have recleaned up the earth leads and the battery is good and with the cap off the points spark well.

I'm at a loss anyone got any suggestions?

[Davemate]

i was going to say cap, but i just re read that you have changed that as well
as a stab in the dark :-
the plugs have to earth out via the engine, is there a good earth on the engine

[nang]

Coil breaking down ?
Tony.

[Oggi]

Good thoughts, but the engine earth is good and I  have just cleaned the contacts and lead, and the coil is only 12 months old.

I have connected the spark plug tester to the coil and get a strong regular spark, could it be the low tension side that is playing up?

Has anyone heard anything about the accuspark stuff on ebay, they are doing a coil distributor and red rotor for �65 is it worth a gamble item is item 180862491253,

I cannot afford to be paying out on maybe fixes so just wondering if anyone has tried this product.

If I was to add an extra engine earth strap where is the best point to go from on the engine to the chassis?

[junkuser]

If the coil is giving a good spark (should at least jump 1/2" at atmospheric pressure) yet erratic spark at plugs, this would suggest there is tracking somewhere after the coil.
Possibly this could be seen in the dark or heard if over a surface but could be inside distributor cap or on the rotor.
Check the inside of the cap for condensation first off.

[Pete Lewis]

old trick to test the rotor.

take off cap, hold main ht lead from coil 10mm above the rotor,  get the engine cranked over , if the spark jumps to the rotor its aerthing thro to the cam,, its stuffed.


if no spark jumps then its fine


Pete

[Davemate]

450 wrote:

1) Has anyone heard anything about the accuspark stuff on ebay, they are doing a coil distributor and red rotor for �65 is it worth a gamble item is item 180862491253,

I cannot afford to be paying out on maybe fixes so just wondering if anyone has tried this product.

2) If I was to add an extra engine earth strap where is the best point to go from on the engine to the chassis?

1)I have one of these Just make sure you have the correct dizzy before you buy !!!!!
http://www.mm-4x4.com/britpart-electronic-conversion-kit-2720-p.asp

2) engine to battery !

[smithy]

peterhlewis wrote:

old trick to test the rotor.

take off cap, hold main ht lead from coil 10mm above the rotor,  get the engine cranked over , if the spark jumps to the rotor its aerthing thro to the cam,, its stuffed.
if no spark jumps then its fine

Pete

...making sure you are yourself well insulated from the HT lead, of course.  ??) ;D

[Oggi]

Well I have tried all the suggestions so far and installed an extra earth and at first still no joy, so I stripped everything cleaned all possible connections again and it ran for a while. but once it was warm it wouldnt fire.

It appears it might be the coil as I noticed it had got very hot whilst the engine was running, surely it's not supposed to get that hot you can hardly touch it?

I will call into Manvers tomorrow if I get back from work in time and pick up a Lucas.

[Pete Lewis]

as herald is fitted with an non ballasted 12v system make sure the new coil  has a 3 ohm primery, you may find the coil you have failing is from a ballasted system and is only 1.5 ohms,  this ups the HT to blow things and consumes twice the current,so can melt points

this may explain the extra heat, yes they get hot but not frying tonight.

make sure the polarity is correct , what ever the battery earth is negative  then the coil -ve goes to the dizzy,  and +ve gets the white feed

wrong way round will heat thing up and obscure misfires turn into failures, with little apparent to see why

just some thoughts

Peter

[piman]

Hello Peter,

the polarity does not cause heating up; the reason for having the polarity correct is so that the current jumps from the hot centre electrode to the earth contact as this encourages electron flow, the same principle as is used in thermionic valves.

Alec

[Oggi]

Thanks Peter, I will double check the connections when I fit the new coil when it arrives. I had trouble sourcing a decent coil locally so ended up buying online.

I have ordered a Lucas gold sport DLB105 non balasted coil, hopefully it will arrive today or tomorrow.

[uksnatcher]

450 wrote:

I have ordered a Lucas gold sport DLB105 non balasted coil

Best you can get, good choice and the optical contacts that Dave has pointed out work well with that coil, i have both fitted and 2.5 years and 7k later no problems at all :)

[Oggi]

It arrived in this mornings post and as I am working from home today I couldnt resist using my lunch break to fit it. What a difference first flick of the key and she is running. I didnt have time to let the engine get warm so cannot tell if all is well on the warm starting but compared to the old coil it is a big improvement.

I will be ordering the kit Dave recommends as well and that will hopefully put an end to this issue.

[Oggi]

Hot start also appears to be OK I just need to fine tune the timing.

Many thanks to all those that made suggestions and recomendations, As always I picked up some useful hints and tips along the way. One of the reasons I like this forum.