Fuel System:
* Clogged Fuel Filter: A clogged filter restricts fuel flow. At idle, enough fuel might get through, but when you accelerate and demand more fuel, the engine starves.
* Faulty Fuel Pump: The pump might be weak, providing enough pressure for idling but not under load. It could be failing or simply not receiving enough power.
* Clogged Fuel Injectors: Similar to a clogged filter, injectors might be partially blocked, limiting fuel delivery under acceleration.
* Low Fuel Pressure: A pressure regulator problem could result in insufficient fuel pressure when the engine needs more.
Ignition System:
* Ignition Coil(s): A failing coil might be able to provide enough spark at idle but not enough power for higher RPMs.
* Spark Plugs/Wires: Worn or damaged spark plugs or wires can cause misfires, especially under load.
* Distributor Cap and Rotor (Older Cars): These components can wear out and cause poor spark distribution, leading to this issue. This is less common in modern vehicles.
Vacuum Leaks:
* Vacuum Hoses: Cracks or disconnections in vacuum hoses can disrupt the proper operation of various engine systems, including fuel delivery and idle control. A major leak can cause the engine to stall when you accelerate.
* Intake Manifold Gasket: A leak in this gasket can cause a major vacuum leak.
Other Possibilities:
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle position. A faulty TPS can cause incorrect fuel delivery.
* Mass Airflow Sensor (MAF): This sensor measures the amount of air entering the engine. A faulty MAF sensor can lead to incorrect fuel mixture calculations.
* Computer (ECU): While less common, a faulty engine control unit can cause this type of problem.
What to do:
1. Check for obvious problems: Look for any loose or disconnected vacuum hoses. Inspect the air intake for any obvious obstructions.
2. Check the fuel: Make sure you have enough gas. Sometimes the fuel pump won't be able to pull fuel from low levels.
3. Consult a mechanic: This problem is best diagnosed by a professional mechanic. They have the tools and expertise to properly diagnose the issue and recommend the best course of action. Trying to fix this yourself without experience can be costly and potentially dangerous.
Don't continue to try and start the car repeatedly if it keeps dying. You could damage the starter motor. Get it towed or have it looked at as soon as possible.
