Crown Victoria LX'93 4, 6L (286 (?) Cid), mileage near 92000.
Done: fuel pressure checked (ok), injectors clean and Ok, adequate compression, catalytic convertor seems to work fine, MAF sensor outputs 0, 5-1V at idle (good, according to rep. Manual).
Known Faults: little white smoke, PCM outputs " EGR solenoid is high" (though the pass from the valve to intake manifold is blocked), oxygen sensors almost dead.
The car has virtually lost much of power in last half of a year. It doesn't accelerate well though max. Speed still reaches 100 mph. When the pedal is depressed the car hesitates and then accelerates slowly. Sometimes surges while driving and has backfire with fast throttle inputs. Just like a gunshot in airbox.
Idle is rough when engine is cold. When engine warms up, no problems with idle.
The co-responding problem (methinks) is poor fuel economy. Maybe 9 or 10 mpg city and highway mixed. The same driving style brought 14 mpg city last year.
What is it? Help, please!
I'm 4000 miles away from any Ford-qualified mechanic so " find a Ford dealer" answer would not help me : )
I have the same problem with my car(94 Crown Vic police) It's exactly the same. I even cleared the passage from the egr valve to the intake manifold and have replaced a lot of minor things on it. The transmission also was totally rebuilt. The tranny works great, but a short while after the performace started decreasing like yours. And it acts exactly the same as what you said yours does. What do you think this is? Wires? Or some sensory gone wrong?
November, 11, 2007 AT 11:08 AM
As I was unable to receive an " in-a-box-solution" from this site so I began my own recearch.
After some driving I examined my spark plugs once again. One cylinder bank had " crystal clear" spark plugs and another had black clogged ones. In a row. One row black one row white.
As I was searching for hints I've found most acceleration and fuel consumption problems dwell in ignition and fuel/air mixture management. And the " white row-black row" is almost certainly an oxygen sensor problem.
My oxygen sensor(s) and spark plugs were killed by coolant leak to a cylinder head with exaust white smoke. And poor gasoline quality in Russia.
So yours may be the same. Just begin fixing with spark plugs. Then oxygen sensors. Hope it will be enough for your P71 : -)