1990 Volvo 740 GLE will the knock sensor cause the car not to start?

Yes, a faulty knock sensor in a 1990 Volvo 740 GLE can potentially prevent the car from starting, though it is not the most common cause. The knock sensor's primary role is to detect engine knocking and adjust ignition timing accordingly. If the engine control unit (ECU) receives incorrect signals from a malfunctioning knock sensor, it could lead to improper fuel-air mixture or timing issues, which might result in starting problems. However, it's essential to check other components as well, as there are many potential reasons for a no-start condition.