Hi Stina
Seems to me there's a rather too much "poke and hope" going on here. My concern is that everyone is assuming a problem with the module rather than looking at the whole system and working through it methodically.
In particular it bothers me that the car doesn't run right on points either. That could well point to some other problem, rather than a timing issue.
So lets start with an audit of what has been done.
1 we have a correctly wired ignition modukle in the distributor.
2 we have a new 12V coil running on a ballasted supply.
3 what state are the ignition leads and distributor cap in?
4 have we established whether the circuit from the starter motor that swaps the coil between ballasted and non ballasted is working?
5 How confident are we that there is a consistant 12V non ballasted and (8V?) non ballasted supply
My instinct is that the problem is going to lie in 4 or 5. We already have eveidence that the SBBC has been seen to work with a ballasted supply (albeit with a ballasted coil).
So what next?
My first port of call would be to carefully go through the fuse box. Check that it has the correct length fuses in it. It is possible to fit metric fuses which are not quite long enough and not quite fat enough. So they don't make solid contact with the blades in the fuse box. Then the fuse box gets warm and the plastic goes soft and lets the blades grip the fuses even less. The fuses should reach right to the end of the blades at both ends. Also check the security of all the wire terminations onto the box. You're looking for something reasonably obvious!
Next up I'd want to check out the paths from the ignition switch to the coil. There are two options.
1 When starting. A supply comes from ternimal 1 of the ignition switch via a white with red trace cable to the gearbox inhibitor switch (Allows start in neutral or park only) and on to the starter motor relay. The relay, when energised, passes this supply on to the starter motor. The throw in of the starter motor then closes a contact connecting the main supply to the motor from the battery to a white with yellow trace cable to the input side of the coil.
2 Normal running. A supply comes from ternminal 3 of the ignition switch via a white cable to the live side of fuse 74. A further white cable runs from the live side of fuse 74 via a 6 way connector to the ballast resistor (as previously stated a length of wire in the loom). At the other end of the ballast resistor the cable changes to white with a yellow stripe and goes to the live side of the coil.
When the starter motor is operating the ballast resistor therefore has a 12V supply on both ends. When running, only at one end, so the other end drops to 7 to 8 V once there is a load on the coil.
From the coil the supply passes through to the distributor where it passes through either the points or the nodule to earth in the body of the didtributor. So another area to check is that there is proper earth from module / points to the distributor base plate and on through to through to the body of the car.
That's all for the LT (low tesion or in this case 12V) side of things.
What about the HT? It must be worth changing the distributor cap. It woldn't be the first time a car has been sidelined by a dodgy distributor cap. And make sure that the clearance between the rotor arm and the centre pillar (usually sprung) of the cap is correct, ie small enough for the two to make good contact, but not so tight that you destroy the terminal in the cap. You could test this by putting a small piece of chewing gum, or similar, on the rotor arm and then putting the cap on - the chewing gum will retain an impression of where the centre pillar cane down to.
Finally the only thing else we haven't looked at is the coil itself. A good engineers maxim is that things only ever fail when they are either really old or really new. The coil is really new so try another coil in its place - any coil will do for the purposes.
Hope that all helps.
Chris
Seems to me there's a rather too much "poke and hope" going on here. My concern is that everyone is assuming a problem with the module rather than looking at the whole system and working through it methodically.
In particular it bothers me that the car doesn't run right on points either. That could well point to some other problem, rather than a timing issue.
So lets start with an audit of what has been done.
1 we have a correctly wired ignition modukle in the distributor.
2 we have a new 12V coil running on a ballasted supply.
3 what state are the ignition leads and distributor cap in?
4 have we established whether the circuit from the starter motor that swaps the coil between ballasted and non ballasted is working?
5 How confident are we that there is a consistant 12V non ballasted and (8V?) non ballasted supply
My instinct is that the problem is going to lie in 4 or 5. We already have eveidence that the SBBC has been seen to work with a ballasted supply (albeit with a ballasted coil).
So what next?
My first port of call would be to carefully go through the fuse box. Check that it has the correct length fuses in it. It is possible to fit metric fuses which are not quite long enough and not quite fat enough. So they don't make solid contact with the blades in the fuse box. Then the fuse box gets warm and the plastic goes soft and lets the blades grip the fuses even less. The fuses should reach right to the end of the blades at both ends. Also check the security of all the wire terminations onto the box. You're looking for something reasonably obvious!
Next up I'd want to check out the paths from the ignition switch to the coil. There are two options.
1 When starting. A supply comes from ternimal 1 of the ignition switch via a white with red trace cable to the gearbox inhibitor switch (Allows start in neutral or park only) and on to the starter motor relay. The relay, when energised, passes this supply on to the starter motor. The throw in of the starter motor then closes a contact connecting the main supply to the motor from the battery to a white with yellow trace cable to the input side of the coil.
2 Normal running. A supply comes from ternminal 3 of the ignition switch via a white cable to the live side of fuse 74. A further white cable runs from the live side of fuse 74 via a 6 way connector to the ballast resistor (as previously stated a length of wire in the loom). At the other end of the ballast resistor the cable changes to white with a yellow stripe and goes to the live side of the coil.
When the starter motor is operating the ballast resistor therefore has a 12V supply on both ends. When running, only at one end, so the other end drops to 7 to 8 V once there is a load on the coil.
From the coil the supply passes through to the distributor where it passes through either the points or the nodule to earth in the body of the didtributor. So another area to check is that there is proper earth from module / points to the distributor base plate and on through to through to the body of the car.
That's all for the LT (low tesion or in this case 12V) side of things.
What about the HT? It must be worth changing the distributor cap. It woldn't be the first time a car has been sidelined by a dodgy distributor cap. And make sure that the clearance between the rotor arm and the centre pillar (usually sprung) of the cap is correct, ie small enough for the two to make good contact, but not so tight that you destroy the terminal in the cap. You could test this by putting a small piece of chewing gum, or similar, on the rotor arm and then putting the cap on - the chewing gum will retain an impression of where the centre pillar cane down to.
Finally the only thing else we haven't looked at is the coil itself. A good engineers maxim is that things only ever fail when they are either really old or really new. The coil is really new so try another coil in its place - any coil will do for the purposes.
Hope that all helps.
Chris
![P260610_11.55_[01].jpg](/data/attachments/1/1683-bc6f879f95b5a8694aedf711839b096d.jpg)
