Posted: Fri Jun 02, 2006 4:52 pm
Hmmm, I suppose the first thing to do would be establish what points/condensor the distributor needs: I don't know whether there is just one type for all 914's? Best to phone someone like Roger Bray, who are familiar with the car: they might be able to tell you what to look for on your dizzy to ensure the correct ones are sent.
Another thing you will need to check is whether you have been left the screws that attach the points, and the other one that attaches the condensor. If you don't think you've got them, again see if you can get them from the same place as the points. If they can't get them then either a Bosch specialist/rebuilder, or model engineers supplier: they are bound to be a B.A. thread of somesort. You might even find you've got them somewhere anyway.
Once you have your points, screws and condensor, you can move on. remove the electronic module, and keep for reference (part numbers etc, just in case you decide to go back to electronic in the future). I can't remember how the 914 dizzy looks inside, but you should find that there is a natural place for the points to attach: usually they locate on a small 'dowel' at one end, have a slotted screw holding them in the centre: the screw going through a elongated hole to allow for points adjustment. The condensor, I think, mounts on the outside of the body of the dizzy on yours (one screw).
You should end up with a wire that comes from the coil negative (might dissappear into the loom and come out near the points?), to the points. At this point another wire should be 'piggybacked' on top of the same wire back to the condensor. Therefore wire from coil negative-points-condensor.
Just to explian what is happening here: the coil is charged up when the points are closed by current flowing into the coil via the +'ve. Imagine the coil is like a battery, which is now charged. When the points open, the stored energy is desperate to go somewhere: it now can't complete the circuit to earth, so an electrical change happens within the coil leading to a bolt of energy flying out of the 'king' H.T. lead (giving the spark). The trouble with this, is that as the points open, the current has some 'momentum', and tries to push across the points (arcing). The condensor is there to act as a 'buffer', and provides an electrical cushion to stop arcing. This is why you should have two wires going to the points: the one that completes the coil circuit, and the other that diverts the residual current to be 'cushioned' by the condensor: I imagine this then either leaks this energy to ground (earth) or shoots it back into the circuit next time the points close?
Anyway back to you car: once you think you have the points and condensor in and wired, you need to set the points gap. Hopefully you've got the measurement in either mm, or 'thou' (of an inch). You may have it as a 'dwell' angle. If so, don't worry! With the ignition off, pop the car into third gear, and with the distributor cap off, roll the car fowards until you can see that the points are as far open as they can be (so the follower is right on top of the cam). Now slacken the mounting screw, and move the points in and out until you have the correct gap: hopefully you've got a set of feeler gauges. If not, just to get you going, just set a gap the thickness of a business card. This should at least be enough to try it.
If it now runs O.K. you will need to get the points finely adjusted using a dwell meter, and then check / have checked the timing with a strobe light. Don't use the car until these have been checked as you can damage the valves or pistons if your timing is out. Having said this, you should be O.K. to 'potter' it somewhere to get it checked, just avoid high speeds or heavy acceleration
.
Hope this helps, any probs give me a shout, and I'll talk you through it
Another thing you will need to check is whether you have been left the screws that attach the points, and the other one that attaches the condensor. If you don't think you've got them, again see if you can get them from the same place as the points. If they can't get them then either a Bosch specialist/rebuilder, or model engineers supplier: they are bound to be a B.A. thread of somesort. You might even find you've got them somewhere anyway.
Once you have your points, screws and condensor, you can move on. remove the electronic module, and keep for reference (part numbers etc, just in case you decide to go back to electronic in the future). I can't remember how the 914 dizzy looks inside, but you should find that there is a natural place for the points to attach: usually they locate on a small 'dowel' at one end, have a slotted screw holding them in the centre: the screw going through a elongated hole to allow for points adjustment. The condensor, I think, mounts on the outside of the body of the dizzy on yours (one screw).
You should end up with a wire that comes from the coil negative (might dissappear into the loom and come out near the points?), to the points. At this point another wire should be 'piggybacked' on top of the same wire back to the condensor. Therefore wire from coil negative-points-condensor.
Just to explian what is happening here: the coil is charged up when the points are closed by current flowing into the coil via the +'ve. Imagine the coil is like a battery, which is now charged. When the points open, the stored energy is desperate to go somewhere: it now can't complete the circuit to earth, so an electrical change happens within the coil leading to a bolt of energy flying out of the 'king' H.T. lead (giving the spark). The trouble with this, is that as the points open, the current has some 'momentum', and tries to push across the points (arcing). The condensor is there to act as a 'buffer', and provides an electrical cushion to stop arcing. This is why you should have two wires going to the points: the one that completes the coil circuit, and the other that diverts the residual current to be 'cushioned' by the condensor: I imagine this then either leaks this energy to ground (earth) or shoots it back into the circuit next time the points close?
Anyway back to you car: once you think you have the points and condensor in and wired, you need to set the points gap. Hopefully you've got the measurement in either mm, or 'thou' (of an inch). You may have it as a 'dwell' angle. If so, don't worry! With the ignition off, pop the car into third gear, and with the distributor cap off, roll the car fowards until you can see that the points are as far open as they can be (so the follower is right on top of the cam). Now slacken the mounting screw, and move the points in and out until you have the correct gap: hopefully you've got a set of feeler gauges. If not, just to get you going, just set a gap the thickness of a business card. This should at least be enough to try it.
If it now runs O.K. you will need to get the points finely adjusted using a dwell meter, and then check / have checked the timing with a strobe light. Don't use the car until these have been checked as you can damage the valves or pistons if your timing is out. Having said this, you should be O.K. to 'potter' it somewhere to get it checked, just avoid high speeds or heavy acceleration
.Hope this helps, any probs give me a shout, and I'll talk you through it
