1990 Honda prelude si is hard to start when sitting out in the heat of the day what could be wrong?

Answer 1

You don't indicate if the vehicle was recently driven. I assume it was not recently driven and it takes a longer period of time to ignite. It's likely that this is because the engine is not getting enough fuel. This occurs because the onboard diagnostic (OBD II) "reads" the engine as NOT needing a "richer" mixture, as during a "cold" start. The possible causes are many. SOLUTION: Assuming the plugs, wires, valves and air filter, are in their correct operating configuration, there is a technique you can try that may help. When you turn the ignition key on, stop at the point just before the car is asked to turn over. You will see the dashboard fully lit. Stay there for about 5 seconds. This lets the fuel pump "charge up" the fuel rail and push as much fuel as possible into the cylinders. Then turn the key to the position that starts the engine. IF THAT DOESN'T WORK, check your air filter and wires. The valves should be adjusted if those items check out. You should be able to remove the air filter, hold it up to sunlight and see the sun's core. The wires can be tested with an ohmmeter - you'll have to ask me about that later. The valves are adjusted with the engine cool.