Hello all, I've recently got my first type 3 (1970 fastback) and I'm having a little problem with it. It's got the standard solex twin carbs on it.
When I start the car from cold it seems to run really rich (VERY strong smell of petrol) and no matter how far up or down I keep my foot on the accelerator, the car is very sluggish and won't pull away at anything more than a very slow crawl. The revs begin to pick up slowly, and once I pick up a bit of speed and get it into 2nd, the car starts behaving pretty normally.
I was wondering if it might be an auto-choke problem, as I had an old van that did a similar thing, which I eventually traced to a faulty auto-choke pull-down device.
Can anyone tell me if the choke mecahnisms on the solex carbs only consist of the electrically heated coil, or are there other parts to them, and whether my problems could be caused by either one or both of these units malfunctioning. Well, really hope someone can give me a few pointers, cheers.
Automatic chokes on twin carbs
Too rich mixture when cold?
There is a pull-down unit with cylinder and piston behind the choke heater unit. There's also a series of notches on a cam in there, similar in idea to the external arrangement on other Solexes. I've not so far fiddled with mine, so not sure what to do in there, but I'll look something up tomorrow. I know some people have problems with the piston not moving.
Check the choke flap is opening, and not jammed. It gradually opens from fully closed due to the electrical heater.
I suspect it may be that the flap isn't opening when air flows through the carb - it should open under acceleration even when first starting form cold.
Before starting the engine that day, take off the air cleaner, and look at the flaps. They should be fully open after the previous run.
Then move the throttle open (at the 3-point arm) and watch the flaps. they should now be closed (full choke).
Start the engine (may need a helper if it's hard to keep running) and watch what happens as you accelerate. The flaps should open in response to the demand for air/fuel.
As the engine warms up, the choke heaters should gradually open the flaps at a similar rate to each other. They sometimes respond rather slowly due to bad connections or high resistance (corroded) heating wires - if so, clean the connections and/or fit new heaters - not sure how easy it is to get new heaters now, but I think some people have fitted the Type 2 ones (left and right are different as they turn opposite ways). Don't change the heaters unless you're sure that's the only answer. It usually just delays the point when the choke opens fully and revs drop to normal idle.
You should now be able to work out if it's the flaps doing something wrong.
If the cold position for the chokes is staying closed too long, the heater clamp screws are loosened and the heater turned to get the flap to do what it should.
Haynes manual has some info on setting these carbs up.
Other note - cold weather can cause fuel to leak through joints that are OK when warmer. Probably not the cause of the fuel smell in this case, but worth checking you haven't got 2 problems.
Check the choke flap is opening, and not jammed. It gradually opens from fully closed due to the electrical heater.
I suspect it may be that the flap isn't opening when air flows through the carb - it should open under acceleration even when first starting form cold.
Before starting the engine that day, take off the air cleaner, and look at the flaps. They should be fully open after the previous run.
Then move the throttle open (at the 3-point arm) and watch the flaps. they should now be closed (full choke).
Start the engine (may need a helper if it's hard to keep running) and watch what happens as you accelerate. The flaps should open in response to the demand for air/fuel.
As the engine warms up, the choke heaters should gradually open the flaps at a similar rate to each other. They sometimes respond rather slowly due to bad connections or high resistance (corroded) heating wires - if so, clean the connections and/or fit new heaters - not sure how easy it is to get new heaters now, but I think some people have fitted the Type 2 ones (left and right are different as they turn opposite ways). Don't change the heaters unless you're sure that's the only answer. It usually just delays the point when the choke opens fully and revs drop to normal idle.
You should now be able to work out if it's the flaps doing something wrong.
If the cold position for the chokes is staying closed too long, the heater clamp screws are loosened and the heater turned to get the flap to do what it should.
Haynes manual has some info on setting these carbs up.
Other note - cold weather can cause fuel to leak through joints that are OK when warmer. Probably not the cause of the fuel smell in this case, but worth checking you haven't got 2 problems.