Hard Starting Chevy

[tucsonjwt]

If you have only cold start problems -
Considering you are in San Fran, then your choke should completely close when you depress the accelerator to the floor once, then remove your foot completely from the accelerator. Once the truck starts, the choke should open almost all the way very quickly, since the ambient temperature is not very cold. If the choke valve is sticking (carboned up, gummed up, etc.) then the air mixture will be too rich and you will have the symptoms you describe. Here is the way I would check this:
1) Depress the accelerator all the way to the floor once - remove foot from accelerator. This should set the choke valve completely closed.
2) Open the hood, remove the air cleaner cover, see if the choke valve is all the way closed - pull back on the throttle bracket all the way while pushing down on the choke valve with your other hand. The choke must be completely shut - just a tiny bit of space between the choke valve and the carburetor will cause the truck not to start. My guess is you will find a slight bit of movement possible in the choke valve when you manually try to move it completely shut. Make sure you pull back on that throttle bracket all the way before pushing the choke valve shut - otherwise the choke valve may still be open slightly but you will think it is closed.
3) Turn the ignition key. If the truck does not start - depress the accelerator half way to the floor.
4) If the truck still does not start, you have verified that it is not because the choke is not closing all the way.
Buy a can of gumout carb spray cleaner and go somewhere the neighbors won't be irritated by you revving the engine. When the engine is good and warm and running, remove air cleaner and pull the throttle back to rev the engine, while spraying carb cleaner on the choke valve, shaft, and throttle linkage. Spray more down the throat of the carb. Don't let the engine stall when your are doing this. Use up the whole big can of carb cleaner. Chances are this won't fix the problem, but your carb will look nice and clean You will then be into a carb repair/rebuild situation. If that is the case, I would look for an experienced Qjet rebuilder who can guarantee the work. I have had no luck with aftermarket brands or exchange rebuilds - others have different experience. Since you are getting good gas mileage on the highway, I doubt that you have any serious problems with that carb. Don't let somebody "fix it" so you get 10 mpg on the highway.