• Tiny
  • samtheman
  • 1995 Mercury Cougar
  • V8
  • 2WD
  • automatic
  • 53 miles

I had a bad misfire for about 2 months, I changed the plug wires and that fixed it.

Now I have a problem with hesitation on acceleration as well as rpm dropping down to 1k rpms while the engine is under load. Note: this only happens when the car is warm, when it is cold it is fine.

Also the cars idle after its warmed up stumbles a little bit.

Things I've Changed:
fuel filter
spark plug
spark plug wires
air filter

Any idea what could cause this?


Do you
have the same problem?
Monday, January 31st, 2011 AT 3:12 AM

1 Reply

  • Tiny
  • rasmataz
  • Member

Could be caused by one of the following below

Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Knock sensor
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note:If it doesn't apply disregard it and keep testing.

Was this
Monday, January 31st, 2011 AT 3:14 AM

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