Weber 2V-ISC Carburetor
Since the idle speed is controlled by a stepper motor, it is not necessary to adjust it manually. If the idle speed does not correspond to the prescribed value, the fault should be looked for using a fault finding program (at a service station).
Note: A CO content deviation of ±0.20% is considered normal. Prerequisite for checking: the exhaust system must be checked. To do this, cover the exhaust pipe with a rag while the engine is running. All pipe connections must be tight.
Caution: When performing the inspection, ensure that the workplace is sufficiently ventilated. Failure to do so may result in poisoning by exhaust gases.
Check the carburetor rods and rollers for gaps. If necessary, repair and adjust the carburetor (service station work).
Warm up the engine and turn it off. The lower coolant hose at the radiator should be warm.
Turn off all electrical consumers (radio, windshield wipers, etc.) and the air conditioning system.
Check and, if necessary, adjust the ignition timing.
The air filter element must be clean. It is best to perform the adjustment after installing a new air filter element.
In accordance with the operating instructions, connect the devices for measuring the crankshaft speed and CO content. Screw on the air filter.
Note: For vehicles with a catalytic converter, the CO content is measured at the CO sampling tube on the exhaust pipe.
Warm up the engine to operating temperature, start it and let it idle.
Check the tightness of the intake tract. To do this, circle all the seals of the intake tract with a brush moistened with gasoline. If the crankshaft speed increases for a short time, there is an additional air leak in the tract. Localize the leak and eliminate the cause.
Warning: Do not inhale gasoline vapors - they are poisonous! Do not allow gasoline to splash onto hot parts and components of the ignition system. Fire hazard!
Run the engine at 3000 rpm for about half a minute, then return to normal idle speed.
Once the readings of the measuring instruments have stabilized, read the measurement results and compare them with the prescribed values, see p. 66.
If the CO content deviates from the prescribed value, remove the protective cap from the adjusting screw "arrow". To do this, drill a hole in the plastic cap in the center, screw a screw or sheet metal screw into the hole and, grasping the screw with pliers, remove it together with the protective cap.
Run the engine at 3000 rpm for about half a minute, then return to normal idle speed.
Turn the adjusting screw "arrow" to set the CO content equal to the prescribed value.
Note: Adjustment must be performed within 30 seconds after the readings have stabilized. Otherwise, run the engine again at a crankshaft speed of 3000 1/min.
Check the idle speed and CO content again.
Install a new protective cap on the CO content adjustment screw.
Remove measuring instruments.
[The original text is provided on an online resource: fordbook.ru]