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.
Have you had the computer scanned? Most nationally recognized parts stores will do it for free.
Let me know.
May, 3, 2010 AT 11:20 AM
Thanks for the reply. Haven't pulled the codes yet. Me the lazy bum.
In this part of the world (Dubai), I wish to have a parts dealer
who would do codes for free.
There's been some development though. The car missing, most of the times
turns into jerks. It almost seems like 1 or more ign-coils are bad.
Is mearsuring coil resistance (when engine is hot) a good way to find the
coil good/bad status? Like I poked an ohm meter into one of the easily
accessible coils today and it gave a 2 4 ohms reading on the ohm meter.
Am I getting some where? Will I get somewhere?
The plot thickens.
Yesterday, the car borke down and won't crank (No power to the solenoid -
Starter motor). Hooked it up to friends car and towed it to a nearby auto
electrician. Early diagnosis, revealed no power in the starter relay.
So, possibly either it is the P/N transmission switch or the key switch that
needs to be further checked. As a temporary solution, the auto-electrician
bypassed the safety checks and inserted a cable into the solenoid realy contacts
to manually start the car by shorting it to the battery. Yeah. I know this is
dangerous. So, I only do it when the car is in park. Parts have been placed
on order. Perhaps within a day or two we'll get this done.
Towing the car wasn't easy. Especially and surprizingly, there was no place
on the bumper re-inforcement to hook the towing rope. So, carefully clamped
it in the middle of the re-inforcement.
Now, I have the SRS light lit up.
Dude I am telling you my panel is lit up with all sorts of lights. Name it.
Check engine, battery, ABS, Emergency brake + SRS Bag (New addition).
And the car still takes me to work. Love this CVPI babe.
May, 3, 2010 AT 4:05 PM
Did they check the starter relay for power?
As far as the coils, can you feel a miss at an idle? If you were to disconnect one coil at a time and reconnect it, would you be able to tell if there is a change in the engine performance? This is old school. Since getting the computer scanned isn't too easy, maybe you could tell which cylender isn't firing by disconnecting coils until you hit one that doesn't make a difference. It's just a thought.
Also, where in the *& % is Dubai? (LOL)
May, 3, 2010 AT 11:47 PM
No power in the starter relay. They traced their way backwards. That is - from the starter towards the trans and ig-switch.
Ok- Will try the coils one by one. Yes there is a small miss in idle but only when the engine is hot. Will see if we can zero in on the coil. The problem is that the missing is at random. Times you feel it and times its smooth.
Dubai (AbuDhabi) is in UAE. Dude. It's the arab oil city next to the Saudi thing. It's got the world's tallest building. For your reference, we are about 12,000 miles away.