jumpy idle in cold weather

[short_mom629]

Hey guys,

I drive a 2000 Expedition Eddie Bauer with the 5.4 engine. Since it has been brutally cold, Im experiencing a jumpy idle at red lights. Within the last 3 months, I have had a tune up, replaced the IAC and MAF sensor. Its making me crazy to two-foot at red lights so that I don't stall out. When the weather is above maybe 20°, it does not jump around. Any thoughts? Maybe a vacuum leak or a dirty TBI?

 

[Lane24]

Try this link.... http://www.expeditionforum.com/f27/rough-idle-p0171-p0174-heres-what-you-need-check-first-4926/

 

[bedrck46]

what is your idle RPM's when stopped at a light?? Also you may want to clean out the exhaust ports inside of the throttle body. Check for vacuum leaks.

 

[short_mom629]

RPMs jump between 700 & 1000 at a red light. Seems to be okayish when in park, but when the weather turns arctic (like the last couple of weeks) it bounces around. Its maddening!

 

[bedrck46]

normal idle should be around 700 when engine is at operating temp, because its jumping up to 1000 sounds more like a vacuum leak Take a can of carb cleaner and spray around the vacuum hoses with engine running and in park with the emg brake on especially behind the intake manifold. If you hear a change in RPM's thats where you have a leak.

 

[short_mom629]

Oops...

RPMs jump between 500-700 at a red light. Sorry!

 

[bedrck46]

still check for vacuum leaks

 

[Notrega]

I think I am experiencing this also but without the change in idle. My idle is between 500 and 600. No change in engine noise but driver and passenger can feel jumpy idle. I'm in North Florida and it as been below 30 degrees and raining the past two days. This started yesterday

 

[EddieH]

Change plugs and wires-Motorcraft Platinum plugs and wires. Stay away from expensive bosch import plugs and Autolite professional series wires-junk.

 

[nonwoven29]

Try this link.... http://www.expeditionforum.com/f27/rough-idle-p0171-p0174-heres-what-you-need-check-first-4926/

Real nice write up Lane!!