Hello to all in this community. Looking for a bit of advice after dismantling the Solex 32 SEIA on my R5 TL 1972. For the first time ever it refused to start during its summer check and after dismissing everything else I took the carburettor off and cleaned it all out and put it back together with new gaskets. I now know that the reason it didn’t start was because I was feeding it diesel, anyway now all cleaned up, all jets and orifices blown through with carb cleaner. It fires up, turns over unevenly for a short while at slow revs and does not respond to throttle, before stalling. Backfires through the carb. Any help would be much appreciated
- Thread starter Nikko
- Start date
André4Renaults
Enthusiast
- Messages
- 812
- Location
- Barnet, Hertfordshire.
Dealing with the consequences of inadvertently adding diesel's not as simple as draining the tank & cleaning the carburettor! You'll probably find you'll need new plugs as well, as the diesel can react with the electrodes. By feeding fresh petrol into the carburettor directly from a can, you can by-pass the tank and the pipe from it. To do this, put 5 litres of premium unleaded (it has more cleaning properties than ordinary unleaded fuel) in a can and run a rubber pipe from the pump's input into the 5 litre can. Spray some Eazystart into the carburettor and start the car, allowing it to warm up normally, having ensured the 5 litre can's securely wedged and can't spill its contents! Once it's warm try to rev the engine. If it revs happily the problem is some residual diesel in the tank and pipe.
This is just a suggestion.......
This is just a suggestion.......
Thank you.
The tank was bypassed using a bottle connected to the pump so I don’t think diesel residue is an issue. After the carburettor clean up the engine did at first start and run for 30 seconds or so, which would have cleaned the plugs. After that it became more and more difficult to start the engine and then it never run for more than 5 or 10 seconds before stalling. Choke in or out or opening the throttle had little or no effect on the revs which were near idling speed. I did not touch the throttle plate adjustment but obviously the air screw and mixture screw settings were disturbed as I cleaned them out.
I am thinking that opening the throttle should have some noticeable effect on the revs if the engine is firing and because nothing much was happening makes me think that something may not be right internally, even though I tried to be super careful when putting it back together.
I understand that backfiring through the carb is a symptom of a weak mixture so I turned in the mixture screw a little. In fact turning the screw in or out had little effect.
Haynes manual is of no use on this. Is there a procedure for setting up a dismantled carb?
Many thanks in advance.
The tank was bypassed using a bottle connected to the pump so I don’t think diesel residue is an issue. After the carburettor clean up the engine did at first start and run for 30 seconds or so, which would have cleaned the plugs. After that it became more and more difficult to start the engine and then it never run for more than 5 or 10 seconds before stalling. Choke in or out or opening the throttle had little or no effect on the revs which were near idling speed. I did not touch the throttle plate adjustment but obviously the air screw and mixture screw settings were disturbed as I cleaned them out.
I am thinking that opening the throttle should have some noticeable effect on the revs if the engine is firing and because nothing much was happening makes me think that something may not be right internally, even though I tried to be super careful when putting it back together.
I understand that backfiring through the carb is a symptom of a weak mixture so I turned in the mixture screw a little. In fact turning the screw in or out had little effect.
Haynes manual is of no use on this. Is there a procedure for setting up a dismantled carb?
Many thanks in advance.
André4Renaults
Enthusiast
- Messages
- 812
- Location
- Barnet, Hertfordshire.
I would proceed as follows, eliminating one thing at a time, so that you'll know what change has caused the difference (if any!) First, are you certain that all the diesel's been cleaned from the carb? If you're not sure, using an aerosol carburettor cleaner should help. Did you remove the carburettor from the manifold to do this? I'd suggest you can't really get into all the jets, crevices and tubes without so doing! Assuming you did remove it, did you change the gasket between the manifold and the carburettor? Is the carburettor now sitting tightly on the manifold? Does the fuel line have an inline filter, and if so, did you change it? What state was it in? If your car doesn't have one, I'd recommend fitting one.
Once all the above has been considered, tuning the carburettor's not too difficult. Assuming the ignition & timing is correctly set and adjusted, gently screw the mixture screw fully in and then turn it out about 2 to 2 1/2 turns. Start the car & allow it to warm up on tick-over. Now use the idle speed (tick-over) adjustment screw to raise the tick-over speed to about 1,500 RPM. Make sure the choke's pushed IN (ie, NOT in use) and then screw the mixture screw slowly in or out, until the engine sounds smooth, without mis-firing or sputtering. Once you're happy with this, turn the idle screw down to allow the tick-over to settle at about 800 RPM.
Go for a drive & see how it feels. You can always fine tune the car after a run, to richen the mixture (screw the mixture screw OUTWARDS) or vice-versa.
Having said all of this, the symptoms you describe sound like a failing condenser!
Once all the above has been considered, tuning the carburettor's not too difficult. Assuming the ignition & timing is correctly set and adjusted, gently screw the mixture screw fully in and then turn it out about 2 to 2 1/2 turns. Start the car & allow it to warm up on tick-over. Now use the idle speed (tick-over) adjustment screw to raise the tick-over speed to about 1,500 RPM. Make sure the choke's pushed IN (ie, NOT in use) and then screw the mixture screw slowly in or out, until the engine sounds smooth, without mis-firing or sputtering. Once you're happy with this, turn the idle screw down to allow the tick-over to settle at about 800 RPM.
Go for a drive & see how it feels. You can always fine tune the car after a run, to richen the mixture (screw the mixture screw OUTWARDS) or vice-versa.
Having said all of this, the symptoms you describe sound like a failing condenser!
I took the carburettor off the manifold and removed all the jets with a screwdriver slot in them and sprayed through all the galleries with a carb cleaner. The only thing I was not sure about was the air correction jet ( the one at a slant) which was turning but was not coming out. New gaskets used throughout.
The condenser is a good call. I have a spare (30 years old) still in its bubble pack. I have already checked the dwell angle but I’ll also check the timing, as too much advance can cause popping through the carburettor. Thanks for the initial setting tips. It does not help that the car was standing for well over a year so a multitude of things could be going on.
The condenser is a good call. I have a spare (30 years old) still in its bubble pack. I have already checked the dwell angle but I’ll also check the timing, as too much advance can cause popping through the carburettor. Thanks for the initial setting tips. It does not help that the car was standing for well over a year so a multitude of things could be going on.