[Ammann]

Ok I have a question about the throttle response on my LJ50.

When I release the throttle, i.e lift foot from the accelerator pedal, it takes several seconds for the revs to drop right down.

A cursory check of the linkages and cable seems to be ok. It drives quite well otherwise but revs drops slow enough that when shifting up the car lurches a little.

Is something wrong here?

[Scrawny]

What kind of carby does it run? Sounds like something sticking inside

[Ammann]

Stock setup entirely except for the fuel pump.

[Scrawny]

But are they side or down draught?

[Ammann]

Ah yes, the 50 has a downdraft solex.

[LittleJeep]

it's the flywheel spinning down. when you are revving the engine the flywheel gets a heap of momentum, when you back off, the compression of the engine isn't enough to bring it back to idle straight away.

how many seconds is several seconds?

[Ammann]

I would say about 7 - 10 seconds. However it can take quite a while for it to get right back to idle. Most of the revs are washed of in say the first 5 seconds then slowly back to idle.

[Scrawny]

Sticky butterfly in the carby?

[sideways]

Does it still do it with the choke on a bit?

[303zuke]

Carb throttle return spring? They can sometimes stretch and fail to snap the throttle plate shut quickly, and after 30-odd years, can become fatigued.

I had a spring fail completely on me once, engine still merrily revved with foot completely off the acc pedal. Only way to stop was turn off ignition key.

[christover1]

side draft su type carbs rev high ,
the only thing stopping it is the throttle cable.
I agree new spring.
(ex moke owner, they used su's)

[3cyl]

As said, they're a downdraught solex type carb. They have a tendancy to rev on a little, mine does, as Littlejeep described. A airleak will contribute to the run on, check the throttle shaft bushes and butterfly also the distributor advance weights, particularly if you are already running too much advance.

[Ammann]

Thanks guys. That gives me a few things for me to inspect. To answer Sideways, it still seems to do it with the choke on a bit, but obviously not as much since the revs are higher anyway with the choke on.