If you have a Chevron station nearby drop in a get a bottle of Techron. Works great, even if you have some long standing crud in the carburetor. This stuff works like a brush in side the carburetor. A little pricey but if it works...
Wal-mart sometimes carries it also. Check with them first. They price it at about 5.00 a bottle. Chevron station will probably charge you close to 10.00.
Techron is a very good product but my personnel favorite is Seafoam. You can buy it at almost any auto parts and marine store, plus Walmart. I have seen Seafoam work miracles on a clogged fuel system. It is also a great fuel stabilizer for you lawn equipment.
carburetor cleaning spray will dissolve old oil and gas tarnish build up in a carb, but it will not remove dirt and grit that has got into the carburetor. Very interesting information here. I have been a carburetor re builder for over 20 years and have found the best method of professional carb cleaning is to use a ultrasonic cleaner.
No for best results the Carburetor needs to be removed and completely disassembled. This helps in cleaning out the jets and small passages, Recommended to be done by an experienced mechanic in that field.
the best additive is a metabond product
Two independent studies rated Opti-Lube XPD as the best diesel fuel additive.
Depends, what do you need the additive to do ?
The Nissan Almera typically uses fuel injection systems rather than a carburetor, as it is a more modern vehicle. If you're looking for information on older models that might have a carburetor, it would generally be located near the engine, mounted on the intake manifold. For specific models and years, it's best to consult the vehicle's service manual for precise details.
I believe that the carburetor type fuel/ air ratio delivery system was replaced by Fuel Injection, no carburetor to the best of my knowledge.
I would try Pony Carburetors. They have a website, and are the best Ford carb people around.
My opinion is that Cerma Stm 3 is the best fuel additive. I use it on my pickup and I went from 17 to 20 mpg's. After you add it to the fuel you'll need to change your fuel filter because it does a really good job cleaning the gunk out. The website explains it in better detail than I can. To learn more about it check out related links.
There is no fuel additive that will increase mileage. This is a myth. None of the snake oil additives work.
Cleaning air duct systems is best done by using high powered vacuum systems which will remove the build up of dust. Using the high powered vacuum through the vents gives the best results and do not forget to reseal the vents when finished.
The best place is the web site.