1.Capacitor.
2.Large Spark plug gap.
3.Low compression due to carbon build up.
4.Pitted points.
5.Timing-dwell-advance.

The only other idea would be to relocate the ignition coil to a cooler location?

I have all new ignition parts as well. I'm sticking to the fuel issue since this condition effects all of my cars with carburetors, not just my 2CV. I wouldn't think it would be that hot in Norway this time of the year

This problem only seems to happen when the temperatures are above 27C.

My Trabant uses a gravity feed fuel delivery system. No fuel pump since the tank is mounted in the engine compartment .One thing that seems to help it start in hot weather (>26 C) is to turn the fuel tap on and wait about 30 seconds before cranking the engine over.

Actually I have a solenoid operated valve connected to one of the coils, but these cars originally came with a fuel tap mounted in the bulk head like on motorcycles (off/on/reserve).

One thing I wondered if it would help the 2CV would be to add a small (250 cc) tank between the fuel pump and carburetor and a check valve before the tank. That way if it is a fuel problem, the tank should act as a buffer. I'm wondering if heat is expanding the fuel in the line and pushing the fuel backwards. So not only is the float bowel empty but so is a portion of the fuel line.

Believe it or not, I had a similar issue with a Fiat X 1/9 that was fuel injected.

I had a theory about that car.

Someone had replaced the (expensive) Bosch fuel pump with one from a Ford. The fuel pressure was correct but when I shut the engine off, I noticed the fuel pressure would bleed off immediately. These Bosch L-jetronic systems should hold fuel pressure for at least a couple of hours. They will bleed off pressure over time.

When the engine was cold, it would fire right up. So it wasn't a lag time of refilling the fuel line but rather having to crank and crank to push any fuel vapors out of the line and through the injectors. That is my theory.

With this car I found that popping the engine cover would relieve the heat and the car would start fine in any weather.

I've tried this same technique with my Trabant and it seems to work. I haven't tried it with the 2CV.

One of the weirdest hot starting issues I ever had was with my 68 Ford. With this car after I finally got it started, it might go a 100 meters when just die.

I then realized the fuel line was touching the upper radiator hose. I had used an aftermarket fuel pump and it disturbed the hose's position. After I replaced the fuel line, that particular problem went away.

Although the car is still hard to start in 27C+ weather just like all of my other carburated cars.

GOT THE BAS***D ! This afternoon (Its about 14 deg C), I had been laying the trail for a 9km cross country walk, stopping off at various points to place markers etc. Lots of 1st and 2nd gear dawdling along bridleways. At one point, it stalled, and would not start. All the usual playing with the accelerator, ign switch etc. Not a glimmer of life. Up with the bonnet and replace the coil - Brrrm! First pull on the starter and away she went. This can be the only reason why Citroen fitted those rubber coil mounting brackets.
Perhaps its time for one of them ECAS coils as I don't see the need for a full blown electronic system on a 602cc AZU.
BobH

I've got one of these fitted to my 2CV.... https://www.ecas2cvparts.co.uk/ignition ... f44697534b

Jonathan, questions:-
1) Is your engine fitted with standard contact breaker and condenser ?
2) How long has the coil been fitted?
3) Approx, how many miles has it done
4) Are you entirely satisfied with the coil and that you don't now have hot start problems?

Apologies for asking so many questions.
Bob

ECAS replied today, Easter Monday. Their 'dry coil' is OK for standard Contact breaker points systems on a 602 engine, so an order will be winging their way pretty soon.
BobH
Ps. It seems the coil gives up after a lot of low RPM idling. I suppose at low revs, the coil is being energised for longer. Another idea, if the dwell angle were too 'long' again the coil would be in circuit longer (Or is the opposite true - We need an expert to respond).

I might be inclined to say that when moving forward there is a quantity of air cooling the coil than when stationary in traffic for lengthy periods, but then all of my A series cars have had plenty of traffic to contend with during their times with me, and I have never had a coil fail - not on a 2cv. The Nissan Micra - yes, and largely due to the horseshoe shaped coil being nestled within a casing attached to the cylinder head. Moreover, most older cars had their coils mounted somewhere under the bonnet. Most bikes had theirs up under the fuel tank, or maybe beneath the seat, though the Villiers two stroke had its tucked inside the generator cover - nice and hot, and like the Micra - prone to failure.

As regards to dwell, this website covers much:
https://spdispark.com/pages/frequently- ... ions-dwell

Gapping points will give a starting point from which to work, using a dwell meter on a running engine will more accurately allow the coil to be correctly charged for optimum spark.

Bob, I'll have a go...
Both of the suggestions you've made do apply and another factor which will contribute to a coil overheating is the charging voltage being too high.
.
Of course, a coil of the correct primary resistance and in good condition should still work OK, even during extended periods of idling or slow running.

This may have been mentioned in the past but are you guys experiencing these hot start conditions in any temperature or just when it get's above a certain ambient temperature?

Every time I've been to the UK (usually in July) it was around 20 C. One year I was there I think it got up to around 25 C. Considering what I am used to in July, this is a holiday in itself to escape the heat.

So today it was 75F/24C.

This is not quite as hot as I would anticipate when my hot starting issues occur with my classic carbureted cars. This usually occurs at 85F/29C and is severely aggravated when it's 95F/35C. As I mentioned this effects ALL of my carbureted cars but seems my 2CV is the worst.

I tried the higher octane petrol thinking this stuff has a higher boiling point than the lower stuff but it doesn't seem to make any difference. I haven't tried 100% petrol, just E10.

I stopped by Subway to pick up a sandwich before heading to work. I expected to be in there for 10 to 15 minutes due to the normal queue of people but must have beat the rush. So I think I was only in there at least 5 minutes, maybe 10 at the most. This is probably not long enough to test.

I got back in and it cranked right up. It seemed to idle fine as well.

I guess it's too soon to tell if the resin filled Harley Davidson ignition coil, new plugs and 8 mm plug wires has solved my hot start problem or not. I may have mentioned I was going to replace the points but after removing the fan discovered someone had converted the car to a 123 ignition system.

As the temperature rises, I'll do a restart every 15 minutes to see what happens.