Hi ya,
The wagon spent a couple of days in the rain and now won't start.
Checked dizzy with cap off and no spark between points. Took lead from coil to dizzy and held dizzy end close to motor while turning over, no spark.
Changed coil over with one that had been kept inside, same thing, so coil is ok i think.
What else stops the coil from sending a spark to the dizzy?
regards,
sigs
no spark
Hi Sigs,
I am holding one hand behind my back with this post - you don't want a repeat of an earlier one I did.
Please forgive me if I appear to assume you do not understand anything - I mean no disrespect, just need to establish the procedure as I understand it.
If you believe the coil is ok - what is needed for a spark to appear is a very abrupt "earthing" of the negative terminal of the coil.
This is done through the contact breaker points in the distributor.
What this does is allows the built up high voltage stored in the coil to discharge from the centre HT output through a number of places and finally across the plug to engine "earth.
This path is from -
1 - HT lead - coil to centre of distributor.
2 - From centre terminal carbon button inside distributor cap to centre of rotor button.
3 - from outer end of rotor button across gap to plug lead terminal inside distributor cap.
4 - from distributor plug lead terminal through plug lead to spark plug.
5 - from spark plug centre electrode of spark plug across gap (this is the reason we have the entire system) to outer electrode and escape through the engine block and discharge the coil.
If you don't have any spark - you may wish to check - that you have 12 volts at the positive terminal of the coil when the ignition is "on"......
you can make up a test lamp for this - if it lights up- the ignition switch and wiring is working.
If that proves OK check that the thin black lead from the distributor to the negative terminal of the coil is not electrically "touching" anything and preventing the coil from charging. This could be anything from the terminal toching the body of the distributor through to this wire's insulation being worn through and touching the body/engine on its way to the coil.
There is one test you can do to prove the "earthing" operation of the distributor -
remove distributor cap and rotor.
turn on ignition
loosen distributor bolt (if you do not know how to re-time your engine don't do this - instead remove plugs and rotate engine).
As distributor shaft turns watch points as they open and close by the six lobes of the cam on the distributor shaft - you should see and hear a small spark appear as the points begin to open.
If that is happening - your primary circuit is functioning - maybe not at the correct time - but functioning and proving that it is at least working.
If you don't get a spark - you may wish to examine the faces of the points for burning, oil, water. Any of these will prevent the small spark from jumping across the points and thus releasing the high voltage from the coil.
Another "trap" is the small copper braided wire inside the distributor - if it is broken - it may cause that initial quick spark to fail.....
You may also wish to replace the condensor - the small cylinder screwed to the body of the distributor. If it is faulty, it won't quickly take the charge of electricity which jumps the points causing them to "burn" instead - you won't hear or see this, it just slowly passes back and won't "spark".
If we have all this so far - we are looking for the reason the coil isn't releasing to the plug.
First thing to check is the Hight tension lead for damage or a broken terminal - you can use one of the plug leads just to check that the coil is working.
Put the rotor button back on, replace the distributor cap and remove the HT (centre) lead from the distributor - turn on ignition, hold lead just away from engine and turn motor over by hand - if you get a spark - there is some problem in getting the spark to make connections through the distributor - check rotor centre button in distributor (it is spring loaded to hold it onto the rotor).
Generally speaking, if there isn't any spark at all - these are the three first steps to check -
power to coil with ignition on.
spark appears across points
spark from coil jumps cnetre lead to engine.
If you have all these and it still will not "fire" - it is most likely a "timing" issue and either the points meed adjusting to get the right "gap" or the distributor nees moving so that the charge from the coil reaches the plug at the correct time when all connections are lined up the instant the cylinder is ready to fire.
If this fails, Sigs - post again and I'll give you some more to look for.
The circuit is very simple - but vulnerable - any one of the above faults will cause it to fail - you mention it was in the rain - I'd check the distibutor cap and inside the distributor for water - also a good wipe with a glean rag -especially the points and points wire - they MUST be clean, dry and contact surfaces "sharply" edged.
frats,
Rosco
I am holding one hand behind my back with this post - you don't want a repeat of an earlier one I did.
Please forgive me if I appear to assume you do not understand anything - I mean no disrespect, just need to establish the procedure as I understand it.
If you believe the coil is ok - what is needed for a spark to appear is a very abrupt "earthing" of the negative terminal of the coil.
This is done through the contact breaker points in the distributor.
What this does is allows the built up high voltage stored in the coil to discharge from the centre HT output through a number of places and finally across the plug to engine "earth.
This path is from -
1 - HT lead - coil to centre of distributor.
2 - From centre terminal carbon button inside distributor cap to centre of rotor button.
3 - from outer end of rotor button across gap to plug lead terminal inside distributor cap.
4 - from distributor plug lead terminal through plug lead to spark plug.
5 - from spark plug centre electrode of spark plug across gap (this is the reason we have the entire system) to outer electrode and escape through the engine block and discharge the coil.
If you don't have any spark - you may wish to check - that you have 12 volts at the positive terminal of the coil when the ignition is "on"......
you can make up a test lamp for this - if it lights up- the ignition switch and wiring is working.
If that proves OK check that the thin black lead from the distributor to the negative terminal of the coil is not electrically "touching" anything and preventing the coil from charging. This could be anything from the terminal toching the body of the distributor through to this wire's insulation being worn through and touching the body/engine on its way to the coil.
There is one test you can do to prove the "earthing" operation of the distributor -
remove distributor cap and rotor.
turn on ignition
loosen distributor bolt (if you do not know how to re-time your engine don't do this - instead remove plugs and rotate engine).
As distributor shaft turns watch points as they open and close by the six lobes of the cam on the distributor shaft - you should see and hear a small spark appear as the points begin to open.
If that is happening - your primary circuit is functioning - maybe not at the correct time - but functioning and proving that it is at least working.
If you don't get a spark - you may wish to examine the faces of the points for burning, oil, water. Any of these will prevent the small spark from jumping across the points and thus releasing the high voltage from the coil.
Another "trap" is the small copper braided wire inside the distributor - if it is broken - it may cause that initial quick spark to fail.....
You may also wish to replace the condensor - the small cylinder screwed to the body of the distributor. If it is faulty, it won't quickly take the charge of electricity which jumps the points causing them to "burn" instead - you won't hear or see this, it just slowly passes back and won't "spark".
If we have all this so far - we are looking for the reason the coil isn't releasing to the plug.
First thing to check is the Hight tension lead for damage or a broken terminal - you can use one of the plug leads just to check that the coil is working.
Put the rotor button back on, replace the distributor cap and remove the HT (centre) lead from the distributor - turn on ignition, hold lead just away from engine and turn motor over by hand - if you get a spark - there is some problem in getting the spark to make connections through the distributor - check rotor centre button in distributor (it is spring loaded to hold it onto the rotor).
Generally speaking, if there isn't any spark at all - these are the three first steps to check -
power to coil with ignition on.
spark appears across points
spark from coil jumps cnetre lead to engine.
If you have all these and it still will not "fire" - it is most likely a "timing" issue and either the points meed adjusting to get the right "gap" or the distributor nees moving so that the charge from the coil reaches the plug at the correct time when all connections are lined up the instant the cylinder is ready to fire.
If this fails, Sigs - post again and I'll give you some more to look for.
The circuit is very simple - but vulnerable - any one of the above faults will cause it to fail - you mention it was in the rain - I'd check the distibutor cap and inside the distributor for water - also a good wipe with a glean rag -especially the points and points wire - they MUST be clean, dry and contact surfaces "sharply" edged.
frats,
Rosco
-
vintageholden
- Posts: 575
- Joined: Fri Sep 07, 2007 5:58 pm
- State: NOT ENTERED
- Location: W.A carlisle 6101
Fixed it, thanks for the advice. I don't think it was earthing on the dizzy properly as Rosco suggested. I ended up pulling the dizzy out and giving it a minor service.
Pulled the points, vacuum advance, everything i could pull off it without dirlling any holes, and degreased all the parts which were covered in oil with prepsol.
Put it back together, with new points. She fired first revolution, sensational sound it was too!!
Thanks again,
Sigs
Pulled the points, vacuum advance, everything i could pull off it without dirlling any holes, and degreased all the parts which were covered in oil with prepsol.
Put it back together, with new points. She fired first revolution, sensational sound it was too!!
Thanks again,
Sigs
Rosco, must have taken you an hour to type that out with one hand behind your back! Nice post mate, took me back to the basics and showed me the problem. cheers againHi Sigs,
I am holding one hand behind my back with this post - you don't want a repeat of an earlier one I did.
mmm, maybe one day :roll:
Glad to hear you're up and running, Sigs...................
Was tossing around in bed last night thinking I may have mis-led you with the spark across the points test - couldn't remember whether it required "earthing" the HT lead ......................my old bus has optronic ignition and it is some very many years since I had to do this test....................
again Sigs - good to hear you're mobile and...
thanks to all others for their input......
re- typing - about ten mins....... (cheated and used both hands - had to stretch my wrist a bit to get it from behind my back, though.............)
frats,
Rosco
Was tossing around in bed last night thinking I may have mis-led you with the spark across the points test - couldn't remember whether it required "earthing" the HT lead ......................my old bus has optronic ignition and it is some very many years since I had to do this test....................
again Sigs - good to hear you're mobile and...
thanks to all others for their input......
re- typing - about ten mins....... (cheated and used both hands - had to stretch my wrist a bit to get it from behind my back, though.............)
frats,
Rosco
