Engine Performance problem
2003 Ford Crown Victoria V8 Two Wheel Drive Automatic 145000 miles
2003, Ford, CV Police Interceptor
Car missing between 40-60MPH on low throttle & normal engine heat.
Car not missing in cold engine.
Engine runs smoothly in low speed and high speed (0-40MPH & above 60MPH).
In 40-60 range, engine especially misses more when there is a gear shift from the auto trans.
In 40-60 range and engine is missing, removing throttle removes missing.
In 40-60 range and engine is missing, high throttle removes missing.
At high throttle, Check Engine flashes ON/OF for some seconds and then stable ON.
Check engine is permanently ON (Purge controller. Will fix it soon)
Car was running good until recently went through a parts replacement (Intake manifold – The whole thing looks like fiber re-enforced body).
Noticed coolant leak from the base of the inlet hose pipe connection. (Upper radiator hosepipe which takes coolant into the engine). Ignored this minor coolant seep and did not top up the coolant until coolant high temp (No indications. It was just the temp gauge that went a few notches up than the normal). That was the time when missing started for the first.
Further diagnose revealed that the intake body was slightly chipped off from the inner side at the coolant entry point and coolant was going into the cylinder as well as shorted the plugs.
Dried the cylinder, replaced plugs, cleaned injectors (they were already clean) and replaced the intake with new. Car was good for ½ hour of test but then the missing started and persists till date. Coolant level is good (Been 3~4 weeks from intake change and drive ave. 30Miles a day) and coolant temp is normal.
Thursday, April 15th, 2010 AT 4:18 AM