Issues with my F4 when its running hot...

[Cowhorns]

I read Sprackers posts with interest. I also have problems with my F4 particularly when it is running hot. (which being in the South of France is often enough.) Basically when the engine heats up it wont tick over and stalls. To get around this I open the choke a little which works. It does tick over fine however when its cool. Also I noticed a couple of times that it sort of hiccups when going up hill. I just lose power literally for a second. Also when I restart the engine when hot it is very uneven.

I have not started to check anything yet. I was thinking starting with the plugs then what? Any advice gladly received.

 

[André4Renaults]

Your car appears to be suffering from what we "old school" mechanics call "vapour lock". The Renault 4 was built when petrol had lead added and this is no longer the case. One of the effects of this is that unleaded petrol has more volatility than is did previously, which causes it to vaporise (evaporate in layman's terms) more easily, thus causing vapour lock to occur more frequently and more often than it would with leaded petrol. Opening the choke enriches the mixture and therefore allows more liquid petrol, as opposed to vapour, to run through the carburettor and so permits the car to keep running. The uneven running when restarting a hot engine is indicative of the same problem.

To solve this you should route the fuel pipes away from any sources of heat, such as the exhaust manifold, and by ensuring the pipes are not passing over the top of the engine, which will exacerbate the problem. Confirming the petrol pump's filter is scrupulously clean and that any in-line filter is similarly in good order are also good actions.

 

[Andy McGhee]

This is the solution the Renault engineers came up with in 1976 - it might help:

Fuel pressure, 'internal seepage' and the T-piece mystery

I'm sure a lot of R4 owners will be familiar with this diagram - it appears in quite a few manuals (most of the text is translated in the Haynes manual). I've seen a lot of posts that say something along the lines of 'One of the T-pieces has a restrictor in it', but I think this is a...

www.renault4.co.uk

You can get the T-pieces here:

Autogrossist Stony Renault i Christiansfeld | Reservedele til veteranbiler

www.renaultdele.dk

 

[reidalpine]

Hi guys! had same problem with my F4 problem solved by running those "silverfoiled" fiber-hoses over all the petrol-hoses i could get to Plus as Andrew says
reroutde the metal-tube that ran over and across top of motor. Also check the thick fiber plate is in place between carb and manifold.. -Reid

 

[JdeW]

I partialy agree with @Andrew4Renaults that unleaded fuel might be an issue. I drove 260.000 miles with my first R4 GTL (since 1987) with unleaded fuel and never had any tick-over or vapour lock driving all over Europe (not Warschau Pact countries) and crossing the Alpes over every thinkable mountain pass.
I think that nowadays regular fuel with the horrible ethanol additive is causing most of the problems.
Here on the mainland you use super 98 or even better the fuel(s) in Germany to run your old timer, just as long there's no ethanol in it.
I agree with @Andy McGhee for the modification and or using the 3 lead fuelpump.

 

[Cowhorns]

Wow what amazing advice. Plenty to keep me going. I use 98 petrol as standard as I heard ethanol rots pipes and seals on pre-ethanol cars. First thing to check is whether or not any of this has been done already. Thanks everyone!

 

[blakeyboy]

I find ethanol rots my pipes and seals.
At least with the cheap stuff.
Single Malts are much better.

 

[reidalpine]

-Too much single malts Do do rot your pipes and drains Blakey -Not to mention your purrformance-system

-Reid

 

[blakeyboy]

....it's five of my one a day....:-)