Cold Start Valve

[Hobo]

Just bought my first Fiat 1982 Spider 2000. The car is a "cold starter", but when temperature reaches 180 the car has a very strong engine. I have not read up on the cold start valve but is this my first area of opportunity: Can the valve be cleaned or does it need replaced, degree of difficluty?

[narfire]

The cold start valve only operates momentarily, perhaps a second or two to aid in the initial start of the engine. You can check it buy taking the two allen bolts out and put the injector into a can and then start the car, see if there is a squirt of fuel. If no squirt, I'd be checking to see if there is power going to the injector with a noids light.
Chris

[wikkid]

Unless he doesn't mean the cold start injector, but rather, the Aux. Air Valve, which opens/closes with a bi-metallic strip to help cold starts. You can clean it and test it yourself.

Here is an excerpt from an excellent fuel injection troubleshooting article:

The AAV is located on the passenger side head cover. It has a standard Bosch electrical connector and a hose connecting to it at each end. It is simple in theory. It has a bimetalic strip inside that expands and contracts when it gets hot or cold. When cold it contracts and opens up a passage inside the AAV which allows more air to pass through it and and into the intake plenum. This causes the AFM to increase injector duration and it increases the idle speed. As the car warms up the AAV's passage closes slowing down the idle. I should note that the idle speed should never really changes much during warm up. The engine will idle at a higher speed as it warms up with a given amount of airflow so what the AAV is actually doing is providing extra air when cold and then cutting off the extra airflow as it warms up to keep the idle about the same. The electrical connection has nothing to do with any other system. It is simply provides electrical current to the AAV to cause it to warm up and close a little faster then it otherwise would. The AAV's most common problem is it gets jammed either open or closed. This happens because the expansion and contraction of the bimetallic strip is not too powerful and it can be easily overcome by oil and crap that gets into the intake system. There are a few ways to check the AAV but only one way is reliable. I am afraid you are going to have to pull the thing off the car. With it off the car clean it out with carb cleaner or something else and then clean out all the carb cleaner with dish soap and water. This cleaning process is needed about once a year on a GTV6 in order to keep an AAV operating in top form. When it's really clean put it in the freezer and when it gets cold look through it and you should see a large opening inside. Now heat it up to about 150F and it should be fully or very very nearly fully closed. If it does not open up fully you will have cold starting and running problems. If it does not close fully you will have an irregular idle and power loss.

Cleaning the AAV almost always seems to fix them. If it doesn't you may try playing with the little adjustment nut on it. It seems that some AAVs close fully, but don't open very far. This is optimum for horsepower but not for starting in near freezing temperatures. Others open a lot giving great cold starting but don't close all the way which robs some horsepower. With the adjustment nut and a lot of patience you can set up your AAV to suit your needs...well, sometimes...maybe. Furthermore if you adjust the AAV you will probably need to re adjust your idle speed. To optimize it for cold starting take a cool AAV that is at least partially open and jam something inside it to keep it from closing. Now loosen the adjustment nut and then force the AAV to open up a little more. Now while holding it open tighten the nut. That will bias the AAV toward effective cold starting. @To bias it toward more horsepower you can just loosen the nut on a warm AAV, it should then close fully. At this point tighten the nut. You will gain a little power but cold starting will suffer. If you fiddle with it enough you can get it to open most of the way and close most of the way which is how most of them work from the factory. If you have cleaned it, adjusted it and still can't get it to open and close properly you will have to buy another.

[Hobo]

Thanks. Really good information, extremely helpful

[kgkmd80]

I went through the trouble shooting process on my 1983 Spider, my issue is the Cold Start Injector that sprays fuel into the intake plenum. It's a BOSCH part (BCH-0280170041) but they no longer manufacture them. Anyone have an idea where to pick one up?
thnx,
Kevin

[wikkid]

Have you tried all the usual vendors?

[124JOE]

http://www.interntionalautoparts.com
http://www.vickautosports.com
http://www.autoricambi.us