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2005 Grand Marquis Problems

Old Jun 19, 2017 | 10:43 PM
  #1  
Dunk's Avatar
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Default 2005 Grand Marquis Problems

Bought this car last week with 34600 miles on it. It's mint and was bought by an 80yr old lady. At 92 she can no longer drive.

Anyway on the way home 3 times this car didn't want to stop at red light and stop signs. Engine revving at 3-4K RPM's.. when I took it out of drive into neutral. Turn the key off and restart she'll idling normal.

Lots of complaints about this on 05's. Even a law suit against Ford in 2014.. Does anyone the cure??
 
Old Jun 20, 2017 | 09:16 AM
  #2  
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Enter your VIN # on a site that checks for re-calls to make sure thatyour car has not been recalled.
If it WAS recalled, make sure that the recall fix has been completed.
Granny may not have been aware of a recall, and it may not have been completed.

Other thoughts --
Disconnect the NEGATIVE terminal of the battery.
Locate and remove the ECM (computer module).
Spray both Male and Female terminals of the ECM with WD-40 and plug the ECM back in.
Leave the battery disconnected for 1 hour.
Connect the battery, start the car, and observe.
If the original problem returns, check the Throttle Positioner and the Throttle Position Sensor.
Parts can be ordered on-line at RockAuto.com.
 
Old Jun 24, 2017 | 03:30 AM
  #3  
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Originally Posted by 95 MERC
Enter your VIN # on a site that checks for re-calls to make sure thatyour car has not been recalled.
If it WAS recalled, make sure that the recall fix has been completed.
Granny may not have been aware of a recall, and it may not have been completed.

Other thoughts --
Disconnect the NEGATIVE terminal of the battery.
Locate and remove the ECM (computer module).
Spray both Male and Female terminals of the ECM with WD-40 and plug the ECM back in.
Leave the battery disconnected for 1 hour.
Connect the battery, start the car, and observe.
If the original problem returns, check the Throttle Positioner and the Throttle Position Sensor.
Parts can be ordered on-line at RockAuto.com.
95 Merc, thanks for that info. I did what you said and haven't had a problem in the last 250 miles...

Let me ask? Why did you think it was a bad connection on the ECM?? And why leave the battery disconnected for 1 hour?

I'm a marine surveyor and I know boats and boat engines, but I've been leasing new trucks since 2000 all Fords. Never had to worry about problems. Like I said sick of endless payments and I don't need a truck anymore..

Just need to get the AC working on this 05 GM...but I do know AC problems.

Also I did clean the throttle body with cleaner. I doubt this car has gone 0-50mph in less than 5 mins with Granny driving it. It is pulling 21mpg around town on the first few tanks of fuel. Thinking about doing an upper combustion chamber cleaning, but I'm going to wait till I make a good highway run..

Thanks for your help..
 
Old Jun 24, 2017 | 07:24 AM
  #4  
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From: Phoenix, AZ., USA
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Hello, Dunk -- I'm glad to be of help.
Your issue seemed to be an electrical problem, so I thought it best to go to the source.
I don't know what climate conditions your rig was run under, so I went after the worst-case scenario (high humidity) that would effect the ECM.
Rather than assume that the ECM crapped out, the connectors were the first line of attack. A thorough cleaning and a shot of WD-40 usually takes care of minor problems on these new, low-voltage computer systems.
FOMOCO tells us that the NEGATIVE battery terminal be disconnected before ANY electrical work is performed. This is to protect the low-voltage parts of the system from being blown out by full battery voltage.
The 1-hour battery disconnect gives ample time for the ECM to "shed" any stored information, and prepare itself to "start over" the learning process.
It usually takes 30-50 miles of driving for the computer to adapt to your driving style, which I'm pretty sure is WAY different from Granny's.
Good Luck !!
 
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