Car model | Engine displacement, cm³ | Carburetor model |
2108 | 1295 | DAAZ-2108 |
21081 | 1100 | DAAZ-21081 |
21083 | 1499 | DAAZ-21083 |
There are three most common reasons for the disappearance of idle speed:
- clogged idle jet of EMC;
- burnout of the EMC;
- lack of power supply to the EMC.
For work you will need: wrenches "8", "10", "12", "13", "14", 12V test light or probe with leads, stripped wire, compressor or air pump.
All the listed carburetors have an electromagnetic valve (EMV) with an idle jet in the idle system. The valve is controlled by an electronic forced idle unit.
[The article is taken from an online resource: VazBook.ru]
1. Remove the air filter housing cover by unscrewing the nut with a 10 mm wrench and unfastening the spring clips.
Remove the air filter. Unscrew the four nuts with an "8" wrench, use a screwdriver to loosen the clamp of the crankcase ventilation hose where it connects to the valve cover and remove the air filter housing.
2. Turn on the ignition. Remove the power wire from the EMC. Try touching the power wire terminal to the EMC terminal several times.
Do you hear distinct clicks when you touch?
No: see point 4.
3. Using a 13 mm wrench (or 12 mm or 14 mm wrench, depending on the version), unscrew the EMC from the carburetor cover. Using two fingers, remove the idle fuel jet. Pay attention to the central hole: remove any debris from it using a compressor or air pump, and make sure the hole is clear. Install the fuel jet in place. Install the EMC in place and tighten it by hand until it stops. Put on the power cable and start the engine.
4. Use the key to "13" ("12" or "14", depending on the version) to remove the ECM from the carburetor cover. Using an additional length of wire, apply the "+" from the battery to the EMC terminal, and use the case to touch the "–" terminal of the battery several times.
Do you hear distinct clicks when you touch?
Yes: see point 6.
5. The EMC has burned out. Replace it with a working one, having checked it first. To get to the nearest auto shop, you can remake the faulty EMC to a forced open one. To do this, remove the idle fuel jet with two fingers, break off the plastic tip of the valve and put the jet back in place. Install the EMC in place and tighten it by hand until it stops. Put on the power cable and start the engine. Keep in mind that when using such a valve, there may be problems with turning off the engine: it will try to work after the ignition is turned off. In such a situation, try not to turn off the engine immediately, but let it idle for at least 5 minutes, and after turning off the ignition, smoothly press the gas pedal all the way down.
6. Install the EMC in place. Turn on the ignition and check with a tester or a test lamp for the presence of "+" on the EMC power wire terminal. If there is no power, the electronic control unit of forced idle speed has failed.
The electronic control unit of forced idle speed cannot be repaired. Replacing it is not difficult, but in order to get to the nearest auto shop, you can temporarily use an additional wire to supply power to the EMC at least from terminal "B" of the ignition coil. Alternatively, you can, having previously bent the rubber cover from the connector of the wire bundle of the forced idle unit, connect the wires on terminals "4" and "6" with a jumper. The numbering order of the terminals is indicated on the cover of the electronic unit to the right and left of the connector - numbers "1" and "7".
Tip: A common engine malfunction associated with the positive idle unit is a significant reduction in engine speed (until it comes to a complete stop) when squeezing the clutch, for example when changing gears or stopping at a traffic light. In this case, to safely get to the auto shop or auto repair shop, it is enough to disconnect the control circuit connector of the forced idle unit, located near the mixture quantity adjustment screw.