Volkswagen Passat B5 2002Р. 1,6 Нестабільна робота двигуна, погано запускається.

Hello everyone, on the repair of the PASSAT B5 2002 with a 1.6 engine. The client complained that the engine starts poorly and the engine is unstable. After doing computer diagnostics, there were errors due to a lean mixture. First, I checked the fuel pump, and as it turned out, the pressure was less than the set one. After replacing the pump, the engine started to start better, but the unstable operation remained. According to the real-time parameters of the lambda probe sensor, it is clear that the mixture is still lean. Then I decided to check the intake for leaks and as it turned out, the system was not tight. After eliminating the air intake, the lambda probe indicators became normal. The engine began to work more stably, but on a warmed-up engine, the start is poor. And at the moment when the start is poor, the control unit gives an error about the throttle valve. After trying to adapt the valve, the control unit gives an error about the impossibility of adaptation. After the choke was dismantled, visually inspected and all power supplies to the choke were checked, it was suggested to replace the choke. The client refused.