Choke Return Spring

[cv01jw]

Afternoon All

I had my first Minor mishap on Sunday when I couldn't get the engine to start after a drive to the car wash. Although I am still very much a beginner I popped the bonnet and (pretended to know what I was doing) worked my way through the ignition and fuel systems looking for obvious faults.

Whilst poking around under the carb I knocked the spring pictured below, which released the arm on the side of the carb. After a minute or so, the car then started and has been fine since then.



I think that the spring is the choke return spring and I am assuming that, if it is not performing correctly, the car will have been running rich. Given the engine was hot when I tried to start it, would it then flood due to the choke being stuck? Sunday was the first time I have needed to pull the choke out (only about 10mm) to get it to fire from cold, and so it may well have been stuck all morning but as the engine was running I didn't notice anything amiss.

If my theory is correct, then I think I may need a new choke return spring - it certainly looked like it has seen better days.

[pgp001]

Hi

That is not the correct spring for the job at all, someone has added that later.
The correct return spring is a torsion type whiich goes around a spigot on the carb body to return the choke lever.

Phil

[cv01jw]

Thanks Phil, I will investigate further.

Would the choke not opening fully cause the symptoms I described, or have I potentially missed the actual reason it wouldn't start?

[biomed32uk]

The springs that Phil mentions can clearly be seen in this picture......

2015-01-25 17.44.36.jpg (1.28 MiB) Viewed 1328 times

[biomed32uk]

Your throttle return spring is also looking tired, if that breaks the results can be a little more hair raising !, may be worth swapping that out as well.

[BrianHawley]

Your throttle return spring is also looking tired, if that breaks the results can be a little more hair raising !, may be worth swapping that out as well.

If that happens at least there is the option to turn off the ignition on most moggies without locking up the steering.

[myoldjalopy]

Yes, my throttle return spring broke once and the car started hurtling down a village road at an alarming speed. Almost by instinct, I put in the clutch to disengage the engine, applied the brakes to stop and then switched off the ignition, wondering what on earth had happened!
A quick peek under the bonnet revealed the answer. Fortunately, no harm done as the road was clear, but a smash - perhaps into the back of another car - is quite possible under such circumstances.

[philthehill]

The throttle return spring bracket attached to the exhaust manifold clamp has not been fitted correctly.
The part of the bracket that secures the throttle return spring should be in line with the end of the throttle cable.
All that is required is to slacken the clamp bolts and re-align the bracket.
Rotating the bracket will also tighten up the throttle return spring.
Check the ends of the return spring where it fits through the upper and lower bracket for wear and if any wear found replace the spring.
To increase or decrease the loading on the accelerator pedal bend the clamp up or down.
As the choke cable is made from piano wire there should be no requirement for a choke return spring. Check that the outer cable has not come away from the choke tube at the dash end of the cable.

[cv01jw]

Philthe hill (and all others)

Many thanks for the help - I will look through my workshop manual to find out what exactly the arrangement should look like and then adjust / realign as necessary.