2002 Taurus rough idle

Tiny
LEENJ
  • MEMBER
  • 2002 FORD TAURUS
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 90,000 MILES
2002 Taurus engine runs rough at idle for first 30 seconds and then smoothes out. Using scan tool the only thing unusual is the ignition advance is only 2 to 3 degrees and then moves up to 10 to 12 degrees as engine smoothes out. What things control the timing?
Thanks. Lee
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Saturday, January 1st, 2011 AT 11:51 PM

10 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
The computer controls the timing based on crank and cam sensors. Have you checked for simple things like vacuum leaks? Has the check engine light come on with any codes?
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Sunday, January 2nd, 2011 AT 12:04 AM
Tiny
LEENJ
  • MEMBER
Get codes P0301 and P0316 once in a while. I have replaced injector #1, changed plugs, checked for vacuum leaks, cleaned mass air sensor, checked: coil, fuel pressure, intake air temp, coolant temp and egr valve. Nothing has changed.
Thanks, Lee
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Sunday, January 2nd, 2011 AT 7:44 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Lee:
Have you ever checked compression in that cylinder? When steel heats, it expands. I wonder if you have a low compression problem only when cold. I know that is a stretch, but the only other thing is the PCM. If you have replaced plugs, injector, fuel pressure is good, and the injector is working properly, it has to be one or the other. One last thought, have you checked the temp sensor?
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Sunday, January 2nd, 2011 AT 6:57 PM
Tiny
LEENJ
  • MEMBER
Still have same problem. Why would the timing ever be set down to 3 degrees for about 20 seconds after starting. There must be some signal that is causing this.
Thanks, Lee
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Wednesday, April 20th, 2011 AT 3:51 AM
Tiny
LEENJ
  • MEMBER
When engine is first started the Ignition advance is 10, it then goes to 12 deg and the rpm is 1508, 3/4 second later it goes to 8 deg and the rpm is 1609, 3/4 seconds later it is 5.5 deg and rpm is 1236, 3/4 seconds later it is 4 deg and rpm 1274, 3/4 seconds later it is 3 deg and rpm 1436, 3/4 seconds later it is 3 deg and rpm 1231, it stays at 3 deg for about 17 seconds and the rpm slowly moves down to around 900. The timing then goes to 6 deg, 3/4 seconds later 7.5 deg, 3/4 seconds later 9 deg, 3/4 seconds later 10.5 deg.
All the time during the timing being at 3 deg the engine runs rough. As soon as the timing gets back up above 10 deg it runs smooth and doesn't miss if you put it in drive.
All sensors are working according to the monitor.
Any help would be appreciated.
Thanks, Lee Jackson
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Wednesday, April 27th, 2011 AT 4:53 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Without being there this is a tough one. The PCM adjust ignition timing. If everything is working properly, that is my guess.
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Wednesday, April 27th, 2011 AT 1:56 PM
Tiny
LEENJ
  • MEMBER
Also, about 4 seconds after the timing goes down to 3 deg, the fuel sys1 goes from open loop to closed loop.
Don't know if that helps any!
Thanks, Lee Jackson
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Thursday, April 28th, 2011 AT 7:44 AM
Tiny
LEENJ
  • MEMBER
Could bad information from the knock sensor cause the timing to be set down to 3 deg for a short period of time? Is there any way to check or bypass the knock sensor?
Thanks again, Lee Jackson
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Friday, April 29th, 2011 AT 6:03 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Yes, the knock sensor os designed to adjust the ignition timing to its most efficient point. If it is bad, it could cause the timing to be adjusted incorrectly.
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Friday, April 29th, 2011 AT 6:25 PM
Tiny
LEENJ
  • MEMBER
I disconnected the knock sensor and nothing changed! Any other ideas?
Thanks, Lee Jackson
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Wednesday, May 4th, 2011 AT 4:56 PM

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