Slow cold starts, rough idle and jerky running are classic signs of worn contact points, a tired ignition coil or a distributor with play in the shaft. On the Volvo 140 the engine code determines which distributor and which ignition parts fit – the B18A with single carburetor, the B18B/D and B20 variants, plus the fuel-injected B20E/F and B30E/F all require different versions. The selection covers distributors by part number and engine, plus combined groups with ignition parts, battery and starter motor. Knowing the exact B-code (B18A, B20A, B20D) before purchase saves time, since the rotor, cap and vacuum advance unit differ between carburetor and injection engines.