well iv been having poor running from the dyane atm, i think this is cos im running the car on low fuel alot (no money) so it some times drags crap from the bottom of the tank into the carb.

I can fix that simply take the tank out and clean it, but my dad just reminded me that im running it on petrol that no longer has lead which the dyane is suppose to be use to (yes i know the engine can handle it).

but the poor car is 32 years old its going to effect it at some point and i thinks its starting to now, so my question is whats the best tablet/liquid lead replacement i should use as theres so many types?

thanks George

George,
I'll bet (something less than a million) that your engine has covered a lot fewer miles than the one in my old Dyane, which still runs well enough to drag a trailer with 6 chassis on it at the legal limit...

Since the intake for the fuel pickup is just above the base of the tank, there's no truth in that old wives' tale about running low on fuel causing problems with running.
It's a carry over from old motorcycles, where switching to 'reserve' did allow sediment at the base of the tank to enter the fuel line.

None of the additives which are available will do a better job of keeping your engine running sweetly than setting your valve clearances regularly, using that setting which corresponds to a 1/4 turn of the adjusting screw.

Some of the cr*p on sale, such as lead, zinc or tin pellets or even magnets will do nothing but lighten your pockets.

ken.

( p.s. Have you re-jetted the carb yet?
If it's still got a 102.5 jet in an 18-26 carb with a Dyane/Ami 'blower' setup, it will not be running well. )

Amen.

George, if you don't have an in-line fuel filter, then perhaps it's worth fitting one. After you're cleaned the tank!

Please, please, please don't get suckered into buying any form of snake-oil 'catalyst' blocks/pellets/magnets for your tank or fuel line.

Yes, there are proper unleaded additives you can buy (which you add in metered doses to your fuel tank) to protect older heads which have softer valve seats, but by all accounts the 2CV is perfectly happy running on unleaded and additives are simply not required.

I understand the recommendation is to have the valve gaps set fractionally larger than was stated in the 'text books'. The reasoning is that the valves will then be open for fractionally less time which means they'll run a little cooler; this is enough to prevent them wearing prematurely.

There hasn't been lead in petrol in the UK for over a decade - and the lead was reduced to virtually nothing long before that - so your Dyane's been running on unleaded or damn-near-unleaded for at least half it's life.

Lead in petrol does two jobs :-
- Protect valve seats. Some valve seats are cut directly into cast iron cylinder heads, and need the protection of lead in petrol, else they start to rapidly erode, leading to valve gaps closing up. On a 2cv, it's not an issue, because the heads are aluminium, which requires hardened inserts even with leaded.
- Increase the octane. 4* was 98 octane, 2* was 92 octane. Modern unleaded is 95 or 98 octane. With the timing set by the book, the 9.0:1 compression engine in Dyanes required 4*, the 8.5:1 engine in 2cvs only required 2*. If the octane's too low for the ignition timing, the engine will pink. If it does, either use 98 unleaded instead of 95, or retard the timing so it doesn't.

One thing it doesn't do, and never has done, is somehow miraculously stop crap blocking the carb. You need a filter to do that.

Not lost on everyone

Hi George .....Just to add to the above,when I first read your post I thought "Oh,plug leads again" .....
A worn set of plug leads can cause all manner of probs in my [somewhat limited] experience.
FWIW ...... I give my '88 2CV a dose of "lead substitute" snake oil every 5 or 6 tankfulls.......[I bought a load of it cheap some years ago,so I might as well use it up]
Also I have an inline fuel filter in the front left hand wheel arch ......[which came in very handy for draining the tank after I stupidly filled my tank with 20litres of diesel upon arriving at last years registers day .....amazingly,the car still ran on the 20/80% mix .....and after draining,it went like the proverbial rocket on the way back home ]

T.

ive run ouboards on a worse mix, will still run fine as long as you dont let the diesel and petrol seperate so your only left with the diesel not a mixture

todays jungle juices seem to all run fine with me,i knw im a late born 2cv but just saying

'Proper' lead-substitute petrol additives such as those manufactured by Castrol, Wynn's and Millers Oils, are required by many classic cars - my Pinto-powered kit car was no exception. These are valid products that do an essential job. We seem to be very fortunate with the 2CV, however, in that we are one of the relatively few pre-unleaded cars that can manage perfectly well without these additives.

My reference to 'snake oil' products are aimed at those 'catalyst', magnetic, pellet bullsh*t - the 'Broquets' of this world - that are still being advertised and sold. They ought to be inserted into the sellers rather than in a petrol tank.

As you can see the consensus is pretty much none!

The petrol has changed its more than just the loss of the lead, there is methanol and ethanol in it, it burns hotter and leaner so the timing needs retarding slightly, and a richer primary main jet-especially if you have a 2cv carb in there, Bhs 7s and do the tappets and it should be good to go.

itll make the small amount of fuel you can afford go further so makes sense

so iv cleaned and emptied the fuel tank

my fuel gauge was sitting just above the zero so assumed there'd be little fuel in the tank. WRONG i managed to fill a bucket! so even tho my fuel gauge needle was sitting at very low i had loads of fuel??

so i drove 10 miles with this fuel thinking that my fuel gauge was inaccurate and i had plenty, but today i broke down because the dyane ran out of fuel! so i filled the tank with £5 of fuel but later that day i also broke down another 4 times because the dyane would not start and when it did start it would cut out every time i revved, and kept mis firing and struggling as if it was starved of fuel???

does this mean my fuel sender is broken or worn, or is my fuel pump acting up. im really confused at the moment.

Help