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Carburettor Icing?

G

gpovanman

More than a 4 is excess!
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I have had a problem with my 4 over the last few days. It has got a hell of a lot colder here over the last week or so, and the car runs like an absolute pig. It starts and ticks over fine, but when on the motorway, especially on the approach to tunnels, it starts to cut out really badly, almost coming to a stop, but if you let the clutch in, it ticks over ok. You can get over the problem to a point by juggling the choke, but it still runs really badly. It is a Spanish model as well. Are these cars prone to having a carb icing problem in cold countries, or is this more like an internal problem with the carburettor? I did not have the tube that connects the air filter to the exhaust, but have fitted one now, and this seems to have cleared the problem up somewhat. Thanks in advance for any answers!
 
My car was a nightmare in the really cold weather on friday morning .I am sure the carb was just too cold. Connect the air pipe that goes to the manifold area and just hope for warmer weather .May be worth picking up a UK air filter housing with the seasonal adjuster fitted .
 
The temperatures here are running at the moment anywhere between 2 degrees above, down to about 7 below, so I think that I will have to hope for warmer weather. I am also thinking about setting up a "third sidelight" under the carb to see if a bit of heating will do the trick. One thing that I have noticed is that when I ease off the gas a bit when it is cutting out, the engine picks up again. I was out in the 101 again yesterday, the 101 having both a water and oil temperature gauge, and I was having a real problem to get the gauges to get off the rest positions, so the problem may just be down to the temperature. One other thing though, and that is that these cars were also produced in Romania, and surely it gets a hell of a lot colder than it does here, but that might just be down to a different carb?
 
I had carb icing returning from the mid winter Renault 4 festival. Symptoms very much like a main jet blocked (which is what the ice does), so no fuel unless the choke is pulled out a bit.

UK cars have a flexible hose attached to the air filter. When it gets below 10 degrees the end of the hose can be fitted over a sleeve on the exhaust manifold so the air filter draws in warm air (the sleeve is missing on my car). Spanish cars have a fixed pick up on the air filter and the top of the air filter can be slackened and twisted around so that the pick up is directly over the exhaust pipe.

Warm air in winter makes a lot of difference to the running generally even apart from icing. If repositioning the air filter doesn't work I can take some photos of a UK set up which is probably more effective.
 
It has gone into the garage this morning, and when I get it back this afternoon, I will be able to tell you what it is! Thankfully, I was in Spain a couple of weeks ago, and brought a carburettor repair kit back with me.
 
wondering is it possible to cover the front grill with silver foil to alleviate this problem?
 
That's a big NO NO unless you fancy replacing a head gasket. The carb should not ice up if the pipe to the air filter is directed onto the exhaust front pipe.
 
freezing carbs

thankyou for your reply.
We are missing the sleeve to attach to the manifold. do you have any ideas
how to get round this?
 
If you can't locate an air hose via Renault or any decent motor factor i'd be very surprised. The Dutch company www.windclassics.nl stock them for 5.95 euros but as I say, any motor factor should have some.

Hope you had a good 'un' Steve, happy New Year.

Rudi.
 
....and a Happy New Year to you too Rudi. Let me know next time you're coming my way as I'd like to take a look at your highly modified car and see how much the 'Pimp My Ride' progamme has influenced you:)

Steve
 
My mechanic spent 3 hours stripping and rebuilding the carb, to find that the problem still persisted. He then changed the fuel filter, and the car runs a dream. What I do find worrying is that I have run 25000 kms this year on Swiss gasoline without problems, but 1000 kms on Repsol's finest, and the filter is blocked. I think I will carry on using Shell!
 
The final result is that the fuel pump has gone west, four months after a new one was fitted. They told me that it is a warranty exchange. I though I would be a smart arse, and got a new one out that I had bought in Spain recently, but the Spanish clowns had sold me one for a R5/7!
 
carburettor icing

just to let you know that we replaced our flexible hose attached to the airfilter and used some basic plastic ties to redirect it onto the manifold, and it is working a treat along the motorway! Everything available from car spares outlet.
 
The problem deepens. The Renault main dealer has told me that the car is fine now. Even though it starts with no choke, even from cold. And is burning twice as much fuel as before. I took it to a carb specialist yesterday, and they pointed out that when you look down into the carb, you can see it dripping, and that when you block the venturi tube (whatever that is) it should cut out, but doesn't. I bought this vehicle thinking that wherever it broke down, some tribesman in a garage in the back of beyond would be able to fix it. I did not count on Renault main dealers themselves not being able to work on them!!
 
Ahhh. It's always annoying when someone messes with your carburettor. If it starts and runs from cold without choke then it is running far too rich. There's a mixture screw on the side of the carburettor body. Screw it all the way in and then out by 1.5 turns and you should need the choke for starting again.

The dripping might be due to a poorly adjusted float in the float chamber. The manual has information about how to set that up.

You'll still be left with the original problem of lean mixture in cold weather. Best way to sort that is positioning the hose on the air filter to suck hot air from the exhaust. The bodge of adjusting the mixture screw by half a turn for the winter isn't quite as effective as the air filter hose hot air mod.
 
Thanks for your input. A new carburettor overhaul kit was used at the time that the carb was (needlessly) opened. It is going to a specialist on Monday. There is also a clonking. I had a "Spurstange" replaced for the MoT, and it made a clonking noise afterwards. Spurstange literally translates as track bar. I took it to the garage again, and they said that they had tightened it up again. It is now making this noise again going round right hand bends, and sounds a bit like a knackered CV joint. I am going to get them to write an engineer's report on their findings, and then throw the lot at Renault Suisse!
 
I went to another garage, and they said that the work that had been done was "Scheiss". They are going to write up an engineer's report that I am going to show to the Renault garage in question. It cost me over 300 quid to have a new carb fitted. I am gutted.
 
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