Engine Lacks Power

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1990 Volkswagen Vanagon, 1990 Volkswagen Jetta, 1990 Volkswagen Golf, 1990 Volkswagen GTI, and 1990 Volkswagen Fox. However, it is still accessible from the selected car via links, so may be relevant.

Test coolant temperature sensor and wiring. Repair or replace as required.
Check fuel system and control system pressure. Replace pressure regulator if necessary.
Check throttle cable adjustment.
Check throttle switch. Adjust or replace as necessary.
Check airflow sensor screen for damage or incorrect installation (if equipped).
Check ignition timing and knock sensor control (if equipped). Adjust as necessary.
Check EGR system for correct operation (if equipped).
Ensure base timing is correct and timing advance system is functional.
Check transmission for correct downshift (auto. trans.)
Check fuel tank filler tube for tampering of restrictor. If tampering has occurred, check catalytic converter for lead contamination and exhaust system restriction.
Check for use of poor quality fuel containing insufficient cleaning additives. Prolonged use of poor quality fuel can cause injector clogging and carbon build-up on intake system.
Inspect intake air element, housing, and preheating system.
Check airflow sensor plate movement. Replace if necessary.