no spark.. changed everything related to the distribution/ignition and still not working!

[Gabriele]

This screw acts as the earth return for the capacitor, so must NOT be insulated. The metal clamp around the casing of the condenser is tightly held in place this screw, which earths the body of the capacitor.

The points and spring should sit on plastic; they ARE insulated from the distributor body. The green wire from the coil passes through the distributor body and connects to the moving part of the points, and none of these parts are earthed to the distributor body. The capacitor IS earthed to the distributor body through the screw securing it to the body, but this screw MUSTN'T touch the spring that tensions the points. I hope this helps!

no, i’m talking about the levered point. it pivots around the little pole from which it’s isolated by a plastic sleeve, but is it supposed to be isolated from the bottom by a washer? if so, the broken washer might be that one, and that might be where it’s shorting out. if not, it’s probably either the condenser screw or the spring and i’ll have to go check

 

[Andy McGhee]

no, i’m talking about the levered point. it pivots around the little pole from which it’s isolated by a plastic sleeve, but is it supposed to be isolated from the bottom by a washer? if so, the broken washer might be that one, and that might be where it’s shorting out. if not, it’s probably either the condenser screw or the spring and i’ll have to go check

Here's a photo that might help - I found an old SEV distributor in the garage:

 

[Gabriele]

Here's a photo that might help - I found an old SEV distributor in the garage:
View attachment 35358

damn that definetely looks like an isolating washer to me! i’ll go double check but i 100% think that’s where the issue is

 

[Andy McGhee]

The plastic sleeve in the points arm provides the insulation from the baseplate, effectively acting as a washer. Could the 'washer' fragment in your distributor be a broken-off part of the sleeve?
What looks like a washer in my photo is an integral part of the baseplate.

 

[André4Renaults]

The plastic sleeve in the points arm provides the insulation from the baseplate, effectively acting as a washer. Could the 'washer' fragment in your distributor be a broken-off part of the sleeve?
What looks like a washer in my photo is an integral part of the baseplate.

Agreed! The spring-loaded points sit on the post that sticks up from the base of the distributor body, but without a washer; the insulation is provided by the plastic sleeve that slides over the post. As the plastic sleeve is slightly longer than the metal part of the points this insulates the points from the post. The plastic sleeve itself would not move, so would just rest on the base of the post and not need a washer. Fitting one would prevent the points from aligning correctly.

 

[Gabriele]

Agreed! The spring-loaded points sit on the post that sticks up from the base of the distributor body, but without a washer; the insulation is provided by the plastic sleeve that slides over the post. As the plastic sleeve is slightly longer than the metal part of the points this insulates the points from the post. The plastic sleeve itself would not move, so would just rest on the base of the post and not need a washer. Fitting one would prevent the points from aligning correctly.

indeed. the points are sitting correctly, and i’ve isolate the source of the short to being the cabe from the ignition coil (this fucker). no short when it’s not connected, shorts when i connect it.
i wonder how! it’s in exactly the same position from the old ignition coil

 

[Gabriele]

the cable

 

[André4Renaults]

Does the short happen when BOTH the wire from the coil AND to the capacitor are connected to the terminal on the side of the distributor body? Try only connecting the wire from the coil and doing the same tests; if the problem disappears then you've solved it-your capacitor is the problem and you need a new one! If the problem's STLL there then it lies in the wiring around the coil. As always, plenty of advice available if you need it-just ask!

 

[Gabriele]

Does the short happen when BOTH the wire from the coil AND to the capacitor are connected to the terminal on the side of the distributor body? Try only connecting the wire from the coil and doing the same tests; if the problem disappears then you've solved it-your capacitor is the problem and you need a new one! If the problem's STLL there then it lies in the wiring around the coil. As always, plenty of advice available if you need it-just ask!

i already checked: it shorts whether or not the capacitor cable is connected. only shorts when i connect the coil, no matter if the capacitor cable is there or not

 

[André4Renaults]

The terminal on the side of the distributor body should be insulated from the body itself. The terminal is there to allow the points to connect to the wire without touching the distributor body (it also allows the capacitor to be connected in parallel) My next "port of call" would be that small terminal; put your meter onto resistance setting and connect one end to the outside of that terminal and the other to the distributor body; there should be infinite resistance (an open circuit). If there's power passing between then terminal and earth, carefully dismantle it and check that everything, as something's wrong there......

 

[Gabriele]

The terminal on the side of the distributor body should be insulated from the body itself. The terminal is there to allow the points to connect to the wire without touching the distributor body (it also allows the capacitor to be connected in parallel) My next "port of call" would be that small terminal; put your meter onto resistance setting and connect one end to the outside of that terminal and the other to the distributor body; there should be infinite resistance (an open circuit). If there's power passing between then terminal and earth, carefully dismantle it and check that everything, as something's wrong there......

you mean like the little screw that comes out right? I had already checked and the little plastic washer that isolates it is fine, and it did give no continuity when the coil wire was disconnected.

 

[Gabriele]

update: i have figured out that the issue is not in the distributor at all, but rather in the 12v cable that goes from the battery to the coil! it’s earthing through that and passing it onto the distributor via the coil.
it’s probably shorted or touching something underneath the dash. that place is a complete mess of cables and i wouldn’t be surprised if there was some fraying or faulty connection.

 

[angel]

When this cable shorts it overheats and melts and you notice it immediately by the smell and smoke.

 

[André4Renaults]

update: i have figured out that the issue is not in the distributor at all, but rather in the 12v cable that goes from the battery to the coil! it’s earthing through that and passing it onto the distributor via the coil.
it’s probably shorted or touching something underneath the dash. that place is a complete mess of cables and i wouldn’t be surprised if there was some fraying or faulty connection.

I'm not sure this IS the cause, for the reasons outlined by others. As I recall the Renault 4's ignition system's isn't fused, so any short-circuit would cause smoke and possibly a fire, as has been suggested. I would carry out the following checks, in this order:
1/ Examine the coil; there are two small terminals, one on each side (apart from the big one in the middle that connects to the distributor.) One of these terminals should be marked with a "+" and the wire from here should run to the ignition switch and then to the battery. When the ignition is switched on there should be a steady 12 volts at the end of this wire. Disconnect this wire from the coil, switch on the ignition & use a meter connected to the end of this wire and earth to confirm that 12 volts is coming through from the switch. If it is, move onto 2:
2/ Having confirmed that 12 volts is reaching the coil, reconnect the wire to the "+" terminal on the coil & check all the spade terminals on the coil are tight. The other small terminal on the coil should be marked with a "-" (or "C.B.") and the wire from this terminal runs to the points inside the distributor. Disconnect this wire from the coil and, using the meter, confirm that with the points are open there is an open circuit between the end of this wire and earth-meaning that when the points are OPEN there's no connection between this wire and earth.

Report back with the results and we'll do the next part..... Or I could fly over to Italy on an EasyJet plane, complete with my tool bag........

 

[JdeW]

A lot of advice is already given by forum members especially by @André4Renaults

The working of the ignition circuit is very very easy as long as the basic criteria are met such as setting the correct timing and point gap (0,4mm).

Here's the theory of operation as I learned it at elementary school electronics, should also work for a junior automotive student

The battery voltage is much too low for a spark plug to spark. The battery voltage is therefore increased to a value of 10,000-30,000 volts using the coil, which is nothing more than a transformer.

The breaker is opened and closed by a polygonal shaft (in a four-cylinder engine this is square) with rounded corners, the distributor shaft. This is usually driven by the engine's camshaft and therefore rotates synchronously with it, at half the speed of the crankshaft. In the rest position, the stop of the breaker rests against a flat side of the distributor shaft and the circuit from the positive pole of the battery is closed by the primary winding of the coil to the negative pole (which is on the chassis). A magnetic field builds up in the coil through induction.

Ignition takes place at the moment that the breaker opens because one of the corners of the distributor shaft reaches the stop and as a result the arm of the breaker lifts (the contact points are opened). At that moment the magnetic field disappears and that causes a very fast (steep) induction current surge with high voltage that discharges over the spark plug. Between the electrodes of the spark plug this high voltage bridges a small distance through the air and that gives the ignition spark.

The capacitor plays an important role in this. Its task is threefold.

1. it absorbs the induction current surge so that no spark occurs between the contact points of the breaker. Without a capacitor the contact points would burn in very quickly.

2. the capacitor together with the self-induction of the coil (they form a so-called LC circuit) ensures an alternating current in the coil that can therefore function as a transformer: a direct current cannot be transformed.

3. the capacitor ensures the highest possible induction voltage. Charging the capacitor at the moment the contact points are opened happens so quickly (the increase is so steep) that the magnetic field of the coil collapses much faster (approx. twenty times faster) than would be the case without a capacitor. In simple terms: the power stored in the coil does not simply flow to the ground, but the coil is, as it were, sucked empty by the capacitor. This creates a much higher voltage peak on the secondary side of the coil, which ensures that a very bright spark is generated between the electrodes of the spark plug.

The high voltage is led to the center connection of the distributor with a spark plug cable, and the rotor mounted on the distributor shaft (and therefore running synchronously) ensures that the high voltage is led to the correct spark plug.

 

[Cornish4]

Personally I would suggest you remove the distributor complete, along with the coil if its an old one, a bin them both. Next, invest in a good quality coil and a 123 electronic ignition distributor. Forget those crappy points and condensor and enjoy trouble free motoring. I know its not cheap, but once fitted you won't regret it.

 

[Gabriele]

I'm not sure this IS the cause, for the reasons outlined by others. As I recall the Renault 4's ignition system's isn't fused, so any short-circuit would cause smoke and possibly a fire, as has been suggested. I would carry out the following checks, in this order:
1/ Examine the coil; there are two small terminals, one on each side (apart from the big one in the middle that connects to the distributor.) One of these terminals should be marked with a "+" and the wire from here should run to the ignition switch and then to the battery. When the ignition is switched on there should be a steady 12 volts at the end of this wire. Disconnect this wire from the coil, switch on the ignition & use a meter connected to the end of this wire and earth to confirm that 12 volts is coming through from the switch. If it is, move onto 2:
2/ Having confirmed that 12 volts is reaching the coil, reconnect the wire to the "+" terminal on the coil & check all the spade terminals on the coil are tight. The other small terminal on the coil should be marked with a "-" (or "C.B.") and the wire from this terminal runs to the points inside the distributor. Disconnect this wire from the coil and, using the meter, confirm that with the points are open there is an open circuit between the end of this wire and earth-meaning that when the points are OPEN there's no connection between this wire and earth.

Report back with the results and we'll do the next part..... Or I could fly over to Italy on an EasyJet plane, complete with my tool bag........

yes, as I've already checked plenty of times before, 12v is getting to the coil.
yes, when the wire that runs from coil to distributor is disconnected from the coil there is no shorting.

 

[André4Renaults]

O.K., we're making progress.... Next questions:
1/ What is the resistance across the coil? To find this, select the maximum resistance setting on your multi-meter (usually 2M ohms) and connect the leads to the two small terminals (the "+" and "-" terminals of the coil) What is the reading and does it remain constant?
2/ Is the bracket supporting the coil tight? This bracket earths the coil's so it should tightly hold the coil in place. If it's loose, tighten it up.

Let's solve this problem!

 

[André4Renaults]

A typical value should be between 0.4 and 2 ohms. A lower reading would suggest there's a short circuit in the coil and a higher reading suggests a partial break somewhere in the wiring. I'll await your answer to the resistance reading.

 

[Cyprusnoddycar]

Personally I would suggest you remove the distributor complete, along with the coil if its an old one, a bin them both. Next, invest in a good quality coil and a 123 electronic ignition distributor. Forget those crappy points and condensor and enjoy trouble free motoring. I know its not cheap, but once fitted you won't regret it.View attachment 35365

Agree ! That's exactly what I did and really worth it. My R4 runs so much better since.