johny

I dont like your comment about the filter being empty. Once fuel has come out of the tank to fill the filter I would think it'll stay filled even if the pump isnt working properly. I wonder if you havent got a lot of debris in the tank which may have come off the interior once you put it back into service and now is blocking the outlet pipe. When you leave it a while some of the debris dislodges and fuel can get through only to sucked back in again when the flow rate increases. Can you check the filter for dirt?

yes your calculations are correct however are you sure your speed/mileage reading is true? Has the car had an overdrive gearbox or non standard tyres fitted?

Think my favourite for a GTIII, easily obtainable wheels, are these JBW offerings:

you sure on that fuel consumption as that sounds amazing! Have to agree with NonMember on the wheels though (think also about the cleaning) as Id prefer period alloys although maybe not minilites.....

Its just a couple of plastic pipes that go from the inlet connections on the standard airbox to a bracket on the RH side of the rad so that the air drawn in is cooler than that in the engine bay. This is particularly helpful when moving slowly when high intake air temperature can cause poor running.....

I can see the welding being quite difficult to get correct and of course much harder to dismantle if its not correct. I think the selector shaft tube will need to seal against the face of the single rail casing (using its normal gasket) and ideally you want to achieve this without having to machine/file the tube flat on the sealing face of the bell housing. You could do this by cutting the necessary clearance hole in the bell housing, preparing the tube with a perfect true end and then bonding it in place while the bell housing is sitting on a completely flat surface....

Clive, I take it the hole in the bell housing has to be drilled/filed out and the area where it goes is a bit irregular isnt it?

Well I dont suppose it'll be as easy as replacing the coil, wheres the fun in that? However at least thatll be one thing to cross off the list and then you can work methodically through the other possibilities. Let us know how you get on.....

Have you considered epoxy metal to bond in the seal tube? If the aluminium is well prepared Ive found it a very effective way of joining it and much easier to carry out than welding. Course its not as strong but in this application I would have thought it more than sufficient....

Yes you could try a direct feed to prove it runs but be careful as the only way to stop the engine if it takes off will be to kill the temporary supply.....

Congratulations that would indicate that you do indeed have the wrong coil! When you get the correct 1.5ohm one installed the same test should give you a voltage reading of about half of the battery voltage ie 6v..... Hope youve understood whats going on and learnt a little bit of electrickery. The ballast resistance is 1.5ohms and the correct coil is 1.5ohms then the voltage to earth at the connection between the two will be exactly half of the 12v supply but if the coil is 3ohms = 2 x 1.5ohms then the voltage reading will be 12/3 x 2 = 8v to earth.

oh that changes everything cos it means your points were open (or a break somewhere) and there wasnt a circuit. Ok well to complete the test you can run a piece of wire from the coil -ve (very important its not the +ve side) to earth to simulate the points being closed and then measure the voltage on coil +ve to earth. Hopefully youll now see ~6v.....

Looks great but whats the verdict? Alright I know it'll need time for everything to bed in.....

hang on with the ignition on you had 12v on coil +ve to earth, 0v coil -ve to earth but 0v coil across the two? That doesnt add up as after the first two readings you should then get 12v across the two terminals....

If you buy a ballast system coil with a resistance of ~1.5 ohms and supply it with 12v continuously it will produce higher sparkplug voltage which will possibly damage high tension components, burn the points excessively and also itself overheat so that I dont think it will run for very long.....

I take it the 0v + to - was without the ignition on? However the 12v and 0v on the coil terminals indicates that something is wrong as a ballasted system should normally only supply ~6v. The only time a ballasted system will supply 12v to the coil is when the starter motor is turning the engine over. So the possibilities are: coil open-circuit (but its 3.5ohmn resistance says no), ballast resistor has been removed or bypassed, contacts on starter motor are permanently closed even when not starting which effectively bypasses the ballast. The fact that you have found a non ballast system coil installed indicates to me that someone has fiddled with this before either as a bodge or intentionally.....

hmmm ok and what volts show on the other terminal of the coil (-ve) to earth - hopefully zero....

ha thats a funny reading! Have you tried the test I described to measure the voltage supply to the coil and end any doubts once and for all about whether your system is modified or not? With that coil resistance I would expect a result of around 9v to earth....

ok if youre certain the system hasnt been modified over the years it should be a ballasted one so you need a 1.5 ohm coil. What was the resistance reading of the old coil across the two terminals with all wires disconnected from them?

oh dear theres still confusion! A 1.5 ohm coil is for a ballasted system and a 3 ohm for a non ballasted set up.... Have you confirmed what your system is?

Looks like normal vapour on a cold day especially as there appears to be a gap between the end of the pipe and the plume which I wouldnt expect if it was smoke....

I read the other day the average annual mileage for classic cars is 900 so its ironic that we worry so much about engine longevity when even a life of only 30k miles equates in many cases to over 30 years motoring🤣

Is it possible to bypass or remove the ballast resistor and so need a 3 ohm coil? I would imagine this is might have been done if the resistor or relay fails so best to check exactly what voltage is being supplied to the coil.....

If you have a ballasted ignition system the coil resistance should be 1.5 ohms and if non ballasted 3 ohms. The coils are not interchangeable. If your not sure which type your system is you could measure the voltage at the coil to confirm it: With the ignition turned on but engine not running measure the voltage to earth at both terminals on the coil. The -ve one going to the distributor points should be zero and the other +ve coming from the supply should show about 6 or 12v with the first indicating a ballasted system (a reading of around 8v would be due to having the wrong coil). If the negative terminal happens to show 12v as well it means the points are open and you need to rotate the engine a little to get them to close. Turn off the ignition while you do this....

If theres no pinking then theres no need to use an octane booster either as an additive or a higher RON fuel in any of our cars. Remember the power available in the fuel isnt changed by its octane level.....