First, you should check the serviceability of the ignition system (see the corresponding section).
Next, you should check the operation of the fuel supply system (see the corresponding section).
All of the hoses listed below should be checked for cracks and their connection points for tightness:
All vacuum hoses, including those that go to the distributor and the "pressure surge" switch, the rigid hose from the mixture regulator to the exhaust manifold, the hoses to the fuel cut-off valves when coasting and stabilizing idle speed. Even small additions of additional air can negatively affect the mixture preparation, since these additions are not measured by the air flow meter. The mixture is thus uncontrollably depleted of additional air.
If the gaskets under the cold start valve and on the injectors are OK, you should check the intake manifold gaskets.
You should look for leaks in the fuel lines.
If the plugs are disconnected and connected repeatedly, poor contact may occur.
The plugs on the injection system parts must look perfect. If necessary, you can bend the tabs with a thin screwdriver.
Caution. When working with the injection system, remember that the system is under pressure for a long time after the engine is turned off. When loosening the bolts, keep a rag handy to prevent fuel from splashing into your eyes.
(Content source: the specified website: audimanual.ru)