Ignition coil

[badbadchimp]

Ok very good to know. I'll have to have that checked by a more capable mechanic than me if the ignition tune ups don't sort the problem out.

[badbadchimp]

Hi again Huib -

I believe my S1 does have a fuel pressure regulator (with glass jar) but I don't see any screw or other valve on the unit that allows me to adjust the pressure or attach a gauge to check what the pressure is. Do you recommend I swap the original out for a current Filter King 67mm and add a pressure gauge to it to dial in the ~0.1 bar you recommend for my Dellortos?

Here is a photo of my current system which show the plastic fuel filter and then what I imagine is the the factory pressure regulator with glass jar, but no apparent screws to adjust pressure or anywhere to even check the pressue.

[Huib]

I can just read the VIN. Your car is a 818.330. The model is Rallye 1.3 without S. It did originally not have a filter nor pressure regulator. The Rallye 1.3S had newer generation carbs requiring 0,2 bar fuel pressure. The Rallye 1.3S was introduced late 1968. Only 152 pcs were produced in 1968. The factory mounted a combination pressure regulator / fuel filter. It was bolted to a special bracket welded to the side of the right front leg.

The device shown on your photo is an aftermarket filter only. As you noted, it does not have a pressure regulator function.

I would mount a paper filter before the pump as on your car. The pump has tiny membranes doing the valve function. Dirt in those valves reduces the efficiency of the pump. Thus mount filter before the pump (unless you have a new tank with a new filter at the bottom and new fuel lines and new ethanol resistant hoses).

Then as you suggest the filter King between pump and carbs on the place where your filter sits now. Be careful when adjusting. The adjust screw almost drops out at the 0,1 bar setting. Pressure a bit over 0.1 is acceptable. Do some trial and error.

The original see through fuel hoses were not unleaded resistant nor ethanol resistant. I see that they were replaced by rubber hoses which are likely unleaded resistant. They don't look ethanol resistant to me. Best replace all fuel hoses by ethanol resistant hoses. Do not forget the short piece of hose connected to the tank.

[badbadchimp]

This is fantastic advice. Thanks again so much, Huib!

The filter below (appearing upside down) the glass jar filter should be sufficient, correct? That is, do I need to replace that, too, or just swap out the glass jar filter for a Filter King and replace hoses with ethanol resistant ones?

JL

[Huib]

Yes. Get rid of the glass jar thingy. Put the Filter King in its place. You may have to unscrew both halves and rotate 180 degrees to get in- and output in the right place. Put a plastic throw away filter before the pump like the one you have now. The one you have looks dirty. Put a new one and put one or two spare filters in the boot. If the tank starts rusting it fouls very very quickly. And yes, put ethanol resistant hoses. Unless of course you only drive in ethanol free countries.

[slyg]

Right.

The primary resistance should be 3.3 Ohm (between 3 Ohm and 3.5 Ohm).
On your Fulvia the coil is probably mounted not vertically but at an angle. It should be epoxy cooled. Not oil cooled. If you shake the coil next to your ear you can hear if there is oil inside. If so, it should be mounted vertically.

The resistance of 3.3 Ohm of the primary is a safety thing. It is there to limit the electric current through coil, points, contact switch, battery if the engine stalls with contact on and points closed. The value can also be achieved by using a coil with say 1,5 Ohm primary resistance and put a high power (> 25 watts) 1,8 Ohm resistor in series.

A so called "Blue Bosch" or "Blue Beru" coil is ok. I should still have a dozen or so Blue Beru's in stock.

@huib, so interesting I tested my coil recently which is mounted on an angle (mine's a 1973 MC), and shook it and could hear it sloosh away inside. It seems to work perfectly fine, and must have from...who knows how long...its maybe a 90s part if not older. What's the theory behind the different mounting and oil to epoxy, and the different age cars? just availability and updated technologies you think? and what could the damage be running the wrong type?

[Huib]

There is a lot of wound wire in the coil which heats up. It needs cooling. In the old days (say before 1970) cooling was done by oil. The coil is not 100% full of oil. To make sure the air bubble is outside the windings the coil has to be mounted upright. On the S1 Fulvia's the coils are mounted upright. For the later epoxy filled coils the position is not important. On the S2 Fulvia's the coils are mounted at an angle. On a 1973 car the mounting bracket is under an angle and it should have an epoxy filled coil.

The primary winding of the coil has resistance. About 3.3 Ohm. This is on purpose to limit the current drawn from the battery if the engine stalls with the contact point closed. In a 12V system the current is limited to 12 / 3.3 = 3.6 Amp. It is this resistance that causes the temperature rise when operating normally. On some Fulvia's the overheating protection is helped by splitting the 3.3 Ohm resistance between the wire in the coil and an external resistor. The coil may have a 1.5 Ohm resistance and the external resistor a 1.8 Ohm resistance.

When you install an electronic ignition like the 123 the current limit is done electronically. You may install a 1.5 Ohm coil. If you do so, remember to also put the original 3.3 Ohm coil, in the boot if you decide to take the original distributor with you as a spare.