Here's a breakdown of the issue and potential solutions:
The Problem:
* Fuel starvation: Your car runs fine at idle because the fuel pump is delivering enough fuel for the engine to run at low speeds.
* Loss of fuel pressure: Under load (driving), the fuel pump can't keep up with the increased demand for fuel. This is the most likely cause given the replaced pump and mileage.
Possible Causes:
* Faulty fuel pump: While you mentioned a new pump, it's possible the new pump is defective or not delivering adequate pressure.
* Clogged fuel filter: A dirty fuel filter can restrict fuel flow, especially under load.
* Fuel line problems: Cracks, kinks, or blockages in the fuel lines can also restrict fuel flow.
* Weak fuel pressure regulator: The regulator may be failing to maintain adequate pressure.
* Engine problems: While less likely, problems with the fuel injectors, intake manifold, or other engine components could contribute to fuel starvation.
Troubleshooting Steps:
1. Check the fuel pressure: A mechanic can use a fuel pressure gauge to test the pressure at the fuel rail. This will confirm if the pump is delivering adequate pressure under load.
2. Inspect the fuel filter: Check if the filter is clogged. Replace it if necessary.
3. Inspect the fuel lines: Look for any visible cracks, kinks, or blockages in the lines.
4. Check the fuel pressure regulator: If the fuel pressure readings are low, the regulator may need to be replaced.
5. Inspect the fuel injectors: Have a mechanic check the fuel injectors for proper operation and clean them if necessary.
Important Notes:
* Safety First: Always be cautious when working around fuel lines and systems. Disconnect the battery to prevent sparks and avoid working in enclosed spaces.
* Professional Help: If you're not comfortable with car repairs, consult a qualified mechanic for diagnosis and repair.
Additional Considerations:
* Fuel quality: Using low-quality fuel can contribute to fuel pump and filter problems.
* Age of the car: The fuel system in a 1995 Corolla is over 25 years old and may have components nearing the end of their lifespan.
By following these steps, you can effectively diagnose and address the fuel starvation issue in your 1995 Toyota Corolla DX.
