Why would a 1988 Vanagon crank but not fire when the weather is hot?

A 1988 Vanagon may crank but not fire in hot weather due to heat-related issues affecting the ignition or fuel systems. Common culprits include a failing ignition coil, which can become heat-sensitive, or vapor lock in the fuel system, where the fuel evaporates before reaching the engine. Additionally, the fuel pump may struggle to deliver adequate pressure in high temperatures. Checking these components can help diagnose the problem.