Thread: HELP please

do you have a spark?

pull lead from dizzy, center one coming from coil. Place the metal tip of the lead near metal on the motor, small gap crank the engine over a see if a spark jumps off the lead tip. No spark? Check that the points are opening and closing, check electrical connections. Still no spark? Problem is in the coil.

Is this telling you to suck eggs?

All the symptoms point to an electrical fault. It is very unlikely to be the distributor as a whole. Take off the distributor cap and check that the points are opening (and closing), and check that there is voltage at the points when open and not when closed. (use a multimeter or a light bulb). If there is no voltage, back track to find where the fault is, most likely a wire off or shorted. Voltage still present with the contacts closed indicates either the contacts are burnt (either oil on them or faulty condenser) or the contact plate is not earthed - this will be a broken earthing wire, internal to the distributor and under the contact plate.

Most likely it is something like the points were not tight and have moved, or a wire is off, but it could be something like a broken rotor button, (should be obvious once the cap is off) or the rubbing block on the points has come adrift, or the centre contact in the cap has fallen out. There is a slight possibility that the distributor was not tightened properly and has moved enough to prevent firing, or was not fully seated and did not properly engage the driving dog, but I think this is very unlikely. To count it out, check the timing approximately by turning the engine (check the distributor is turning) until you see the points start to open and check that the pointer is close to the timing mark.

There is a possibility that the coil HT lead is loose in either the coil or the distributor cap.

Hope this helps
John

Thanks for the info, ill check the coil tommorrow and the voltage on the points, i checked the timing after i got her home and it was still good, also i checked the pionts, they were nice and tight and still the same as installed. I may even give MR Automotive a call in the morning and see if any ideas, as i bought the dizzy off then today

http://www.aulro.com/afvb/555722-post7.html

get one of them..

plug a 3w test light across the coils LT terminals and slowly turn the engine over using the crank handle with the ignition on and watch the timing marks while your at it...

IF all that works then the 12v side is all good with the possable exception of the condensor. if it doesnt its simple 12v fault finding from here... if it lights then... (a shorted coil will not let the bulb light and will take out the fuse, use the test light to check the +ve supply to the coil before starting the tests with it across the coil)

plug a test plug into the HT lead on the coil and crank again with the ignition on and the test lamp removed.. It should spark, if not then the coil or the HT lead is out, swap the HT lead and go again...

after that its dizzy related check the rotor and the rotor button in the cap to make sure they are both Ok and make sure the rotor button hasnt skipped on the shaft...

reseat the dizzy cap and if youve had spark on the main lead and inside the cap is all good pull of one of the spark plug leads put it on the test plug and after double checking the HT coil lead and the plug leads for security and order crank the engine till the test plug sparks again... (or fault find the HT side if it doesnt.

Thanks to all for the help, i ended up today getting a new coil and HT lead, put them on and the car started but was running like a dog so i rechecked the timming and gaps, all looked good so i had had enough and to satisfy myself i refitted the old dizzy, the car started and runs like a dream. I rang Dwayne at M R and he said to bring it back and they will swap with another, he is buggared if he knows why it would be like that but certainly didnt hesitate in wanting to swap the dizzy.

I certainly cant see if i did anything rong, when i fitted it she ran sweet as and it wasnt till an hour or so latter when i drove it that something went rong

wrong advance plate and weights in the mech advance section...

if they were sticking while you started out it would have run fine but then when it goes west you can get all manner of hell...

doesnt usually stop the engine tho just makes it run like a dog.

you might have got 2 faults in one... the dizzy which was conveniently hidden by the coil failing....

Ok i took the dizzy bake on Thursday and they exchanged it, i fitted the new one yesterday and she is running like a dream, starts easy when cold, doesnt hesitate on take off like it used to but when hot she still wants to run on after turning the key off ?????? any suggestions to remidy this, i read in the manual that the carbon canister can cause some of these symptons but she doesnt have one so it can be that.

usually 1 of 3 things

1. the contacts in your ignition switch are sticking, but IVe only seen that a handfull of times and never yet in a landy

2. youve been running rich and have carbon build up somewhere and thats making a hot spot (like a glow plug in a diesel) and the engine will keep running with it as it, bet it makes horrid knock while its going. take her out for a nice hard run after retuning the carby and stop occasionally to spritz a little water into the intake without the air intake duct in place, put it back and go again.

3. some idiot has wired the ignition/alternator wrong and while the alternator is making power its keeping the coil going, this ones easy to prove hold it at about 1000 RPM and turn the key off if it keeps going then your wired up incorrectly..

watch what the engine does when it wants to run on... if its running backwards then its also a running rich thing.