R18/Fuego Carb Autochoke problems

[mkatgert]

Hello everybody.

I'm new here, and i'm the owner of a 1982 Fuego 1.6 GTS.

Recently my waterpump jammed on a freeway, but with a fast response i was able to stop the engine just in time for overheating.

After mounting a new waterpump and checking the valve clearances the engine sounds as new.

The only things left are some problems with the automatic choke.

It's a Weber 32 DARA 38 carburettor with the choke adjusted by the temperature of the coolant.

When i want to start the engine cold, i have to depress the accelerator, after which cam 3 turns in order to block screw 1. This screw 1 prevents the throttle butterfly to close completely and therefore raises the idle RPM.

When i do not touch the accelerator, the cold engine runs fine. When i depress the accelerator once more, cam 3 turns away and the idle RPM lowers to 750 RPM, which is too low for the engine to run smoothly. It will keep running but it shakes terribly.

Am i correct that this is due to the fact that the throttle butterfly closes? Or can it be caused by an incorrect choke flap setting? I can not find a way to prevent the revs to drop to 750; turning screw 1 does not have any effect once cam 3 has turned away...

Any ideas? Thanks in advance...

 

[psgold67]

Hello everybody.

The only things left are some problems with the automatic choke.

Any ideas? Thanks in advance...

welcome to the club, is the cam set by a bi-metal spring inside the housing?

check the condition and operation of that first, I had a similar problem on a Ford and endedup swapping for a manual choke

Paul

 

[mkatgert]

is the cam set by a bi-metal spring inside the housing?

Thanks for the reply. The cam is set by lever (2) which is set by a bi-metal spring. I somehow assumed this spring would be in good condition, but it might as well be broken down by the hot coolant. Thanks for the tip, i have a spare carburettor and therefore a spare bi-metal spring, so it's a good idea to have a look at it.

 

[Chris H]

well the choke is operating fine if its workign which you say it is.

The issue is the normal idle speed, 750 rpm's is about right for the engine. The probalme may be either too rich or more likely to lean an idle mixture so adjust the mixture screw

 

[mkatgert]

well the choke is operating fine if its workign which you say it is.

The issue is the normal idle speed, 750 rpm's is about right for the engine. The probalme may be either too rich or more likely to lean an idle mixture so adjust the mixture screw

Thanks for the reply.

Funny thing is that, once the engine has reached normal operating temperature, the engine idles very smoothly. Therefore I doubt whether it has something to do with the idle mixture.

I'm lucky to have a spare carburettor, so i can play with the levers and cams a little bit

Does somebody know how to test the bi-metal? I submerged the chamber connected to the coolant with hot water, but the spring did not react... Do I have to wait a little before it will expand?