Winter sort-out

[apriliadriver]

I had been troubled by a more-or-less random misfire most of the year, accompanied by a loss of power. On taking it to the engineers a few weeks ago, what transpired was (as always) a combination of several things and a possibly fuel-related set of issues which might be of interest to pre-war Lancia drivers (the cars, that is, not the drivers ....).

Prior to the visit, I had tried all the normal things  -  checked out the diz, replaced the diz cap/rotor arm, checked the fuel flow, checked the spark-plug connectors for good contacts, and etc.

On further checking & testing by skilled engineers, the following emerged : one of the spark plug connectors was definitely duff and the problem centred on a poor connection between the spring loaded cap within the bakelite tube and the metal rod that goes from the spring-load cap to the brass insert at the top of the cap. The amount of crud and (surprisingly) corrosion inside the spring load mechanism was astonishing. There is no positive connection between the spring load cap and the metal rod which after the passage of time can be a problem.

The next issue was that the mazak venturi in the Weber DR5 36 had broken up  -  severely cracked and fell to bits on removal. Finding a similar-size venturi to adapt was a pain.

Finally, though, there was severe delamination on the inside of the short lengths of high-quality rubber/fabric fuel hose that join up the long metal pipe runs between tank and carb. The engineer told me that in recent months they have experienced a sudden spate of similar instances on pre- and post-war cars (and some as recent as 2005 manufacture) which they believe is to do with the higher bio-ethanol content of modern 97 RON fuel. There was also corrosion wear in the fuel-pressure regulator, all of which conspired to cause a fuel-flow restriction. They are now using a different flexible hose which is allegedly proof against bio-eth disruption.

I should add that in the UK I tend to fill up at BP or Shell stations in the UK generally, but over a 1000 mile trip to Angouleme and back, I was filling up at French supermarket petrol stations. I am now using a Miller additive, VSPe.

In the midst of all this, (and unrelated) it became clear that the big-end shells were waving goodbye on their way to the junkpile in the sky. The original fitment had been a Glacier shell common to the Renault 4CV and the Renault 5, but the bearing material looked defective and had been hammered by the intervening 3 years/5500 miles. So that's enough bad news for one day.

But if you are chasing what appears to be a fuel-flow problem, you might want to check whether any flexible pipes are suffering from this new fuel formula.
Nick

[simonandjuliet]

It is always a pain when there are several factors conspiring against you ! Sorry to hear about the big ends though, that is going to take more than a few minutes to sort out 

RE plug connectors, I replaced mine with new ones ( reproduced by our friends in Mulbarton) and am very happy with them.

Re petrol, I use 95 French supermarket petrol every day in my R4's and have covered thousands of kms . I have never had any delaminating hoses in more than 8 years of R4 use, so I would be surprised if it was that. However I have just replaced all by fuel pipe on the Aprilia with the braided type, so will keep an eye on it , thanks !

[peteracs]

Hi

Interesting comment about the rubber fuel pipes. There was a comment recently on the Stratosec forum, where it was suggested to avoid rubber fuel pipes and go for PTFE due to modern fuel mixes.

Not sure if this link is members only section, but here we go.

http://www.stratosec.com/Forum/showthread.php/91-My-first-Kit-Car-Hawk-HF3000/page17?highlight=ptfe

Peter

[fay66]

Hi

Interesting comment about the rubber fuel pipes. There was a comment recently on the Stratosec forum, where it was suggested to avoid rubber fuel pipes and go for PTFE due to modern fuel mixes.

Not sure if this link is members only section, but here we go.

http://www.stratosec.com/Forum/showthread.php/91-My-first-Kit-Car-Hawk-HF3000/page17?highlight=ptfe

Peter

Peter,
Yes it is, you have to sign up before you can access the site.
Brian
8227

[Sebastien]

RE plug connectors, and misfiring:
I remember well this small article by Paul Vellacott, relating his experiences, and his solutions.

The link might be worth posting:
http://www.viva-lancia.com/snippet/snippet7.htm

[peteracs]

Brian,

Ok, this was the most interesting post about the braided pipes.

"With all the various chemicals in fuel and oil these days, I wouldnt take the chance with braided rubber lines. Ptfe is way better and the similar cost, no brainer.
Check out all the works racing/rally cars.
Iirc, Tim had some braided rubber fuel hose on his Corse which was marketed as stainless braided rubber injection hose. The stuff just rotted away in a very short timescale. Could have caused a fire very easily. "

Peter