| Author |
Message |
    
Tony Vinson (62.31.224.1)
| | Posted on Tuesday, 10 December, 2002 - 06:37: |    |
On the top of the B-bank air intake (large steel U-pipe) there is an electrical component fastened into place with 2 screws, with wires which are connected to the coil circuit.
Does anybody know what it is?
It looks like it might be an electro-magnet for holding the auto-choke open, the lower end is mounted just above a lever for actuating the auto-choke.
I need to know, because mine has started smoking and blowing fuses on the ignition circuit! |
Bill Coburn (203.51.32.90)
| | Posted on Tuesday, 10 December, 2002 - 08:37: | |
Tony/ This was one of a few stop gap gadgets installed on all carburetted cars from about the 'M' series Mk VI Bentley and was prompted by the demand for an automatic choke. As you know these engines are choked simply by closing the massive butterfly in the air intake as distinct from dropping the main jets in the earlier cars. The butterfly is moved and shut by the thermocoils in the choke housing beside the intake. Because of the size of the butterfly and the need to keep it firmly closed when starting particularly in very cold weather, additional means were needed to keep it shut and the designers did this with an electromagnet. What you can see is the terminal cover for this magnet which is held on by a wire clip. The circuit does not operate until a very low temerature so there should be no trouble disconnecting it at the cover and tracing the fault. The circuit incidentally goes through an Otter switch which 'makes' at the prescribed low temperature and a Scintilla Switch which 'breaks' after carrying current for a short time. These are designed to avoid the electromagnet coming on unnecessarily and choking the poor thing to death!! |
Bill Coburn (203.51.32.90)
| | Posted on Tuesday, 10 December, 2002 - 08:40: | |
Afterthought. I am forgetting this is a much later car. There is no cover. The electromagnet is fed by installed wiring with external connectors. Disconnect them. The magnet can be replaced by simply releasing the two screws retaining it. |
Tony Vinson (194.117.133.118)
| | Posted on Tuesday, 10 December, 2002 - 11:27: | |
Many thanks for your advice.
It sounds pretty much as I had suspected, I've disconnected the unit to allow me to get the car back under cover.
It also explains why the problem didn't show over the Summer/Autumn - the temperature here has suddenly dropped to near freezing so this may be the first time the unit has activated for months.
I'm now having problems with stalling, so evidently the magnet is required.
I'll order a replacement tomorrow - at least it's easy to fit!
Thanks again. |