auto choke back to manual

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auto choke back to manual

Post by tanker108 » Mon Nov 07, 2005 8:30 pm

I have a 1978 Fiat Spider with the automatic choke "mechanic" has tried to repair, to no avail..will not hold at idle..what "kit" can I buy to return my Spider to its original manual choke condition..Thanks for your input, am not a mechanic

Richard Puckett
Then..A new 1971 Spider
Now...A used 1978 Spider
Thanks for all the help..I "think" I have it fixed. Time will tell

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Dwight V.
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Post by Dwight V. » Tue Nov 08, 2005 8:29 am

Sounds like a mechanic that knows very little about carb operation.

The '78 should likely have a water temp controlled choke. Coolant enters the round choke housing hanging on the side of the carb and affects the bimetal spring located within. As the coolant warms, the spring tension changes, and the choke progressively opens. Other than sticky linkage, the only thing that should go wrong with the choke is the spring inside <i>can</i> go bad, though it's pretty rare. It is sold seperately, and fairly easy to replace, though it does have to be 'set' to an adjustment spec when installed (also not hard to do with a manual and basic reading comprehension skills).

Now, completely unrelated to this is the idle stop solenoid. It's a miniature soda can with a wire going to it. The purpose of this device is to cut fuel when the key is turned off to prevent that annoying 'dieseling' that often occurred on emissions era cars. If the wire is loose/off, solenoid loose or defective, or if it is not getting power from the switch the car will receive no fuel at idle...and messing with the choke will do nothing to fix it.

Simple check on the choke system you can do with no mechanic skills: with the car cold and not running, remove the air cleaner top and peer at the two barrels of the carb. The top butterflies should be open fully (or almost fully) from your last drive. In the car, push the gas pedal down once. The butterflies should snap to a 3/4 to near fully closed position. If they don't, you have a choke problem. If they do, you have another problem.

Then, seek a new mechanic. [;)]

Co-founder, FLU
23 Fiats since 1982

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Post by janet70 » Tue Nov 08, 2005 10:22 am

On my 1978 the idle stop solenoid was the problem. Car wouldn't start at all until I fixed this. Easy fix, it just screws in.
Another common problem with the '78 is when the one-way fuel valve fails, and you can't start the car without massive amounts of starter fluid until the fuel finds its way back up to the carb. The one way valve prevents the fuel from draining backward. Now that I know this stuff, I wish I would have kept my '78 and fixed up the body!

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Post by rpconlon » Thu Nov 10, 2005 2:44 pm

Take the top off the air filter box. The warm car should have the choke flap open. If it is and the car idles badly then look for another cause. If it is closed, prop it open with a stick and expect the car to idle well. If not, then look for other problems.
A drop of oil on the flap fixed my sticky choke.


Ron Conlon
Roamin' Chariots

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