2001 sport trac 4.0 cold/rough idle to cut off

[allredneck]

when cold the sporty acts up like a child getting up for school... it runs rough cuts off and generally runs like it has serious ignition issues,, replaced the egr positioning sensor, changed the air filter ,and fuel filter.. plugs too... this only happen when it is cold... hot no problem... CEL is on also.. reset it after all that and it is BACK on... any ideas anyone???

 

[shiphorns]

If the CEL is on, have you read the code? And what do you mean by "cold", your profile shows you're in FLA.

 

[aldive]

Have you checked the IAC?

 

[sport01mi]

I'm having the same problem...its actually at the dealer right now and they don't even want to do the 00m12 recall work on it, which I personally think is the problem. I'm 3 months out of warranty but I got a hookup and they said they'd do it for me. Now, they can't duplicate the problem I have every cold morning I go to start it up and it rough idles and cuts off or smoothes out after about 2-5 minutes running and lightly revving the engine. I've cleaned MAF, Replaced IAC, Cleaned TB, Plugs and wires were replaced last year..Not throwing codes or anything though..

Can anyone else think of any other possible causes? I'm leaning towards an injector problem or possibly an o2 or even PCV? Then again, it would be throwing codes if it were o2?? Thanks, this problem is getting on my nerves and so is the dealer that is doubting me.

 

[WanderR]

Had the same issue a couple of months back.Whats happening is that when the engine is cold (ambient temp) around 45F,injectors richen-up by increasing the duty cycle,which makes it run rich like a choke on an old carb.Whats happening is that the 6 o-rings at the base of the plenium have started to become brittle and allow air to enter the manifold.Once engine reaches operating temp,the plenium,manifold and orings expand and seal it off.
Spend $20.00 and about 2 hrs with simple hand tools and remove the plenium and replace the 6 orings.......pretty common problem

 

[shawneeleelee]

I am having the same problem today. Been going on for several months and has been getting worse over time.
I wonder if WanderR is still around?
His solution makes sense to me, but I got one question.
I am getting DTC codes P0171 and P0174, which are Bank 1 and 2 System Too Lean.
WanderR says the system in running to rich when cold.
Could it be the same thing?
Thx - Ford Man for Life

 

[stilbo]

"Too lean" = Too much air (O2).

Your O2 sensor is reading the exhaust and sees extra O2......

Extra O2 probably is from a vacuum leak.

Ron S.

 

[shawneeleelee]

Thanks Stilbo,
Makes what WanderR says make sense. Rough idle when cold, but after it warms up it runs fine. Rough idle at start up has progressively gotten worse, but after it warms up, it runs fine.
115k+ miles, so I think I will try what he suggests. Sounds like a relatively easy chore.
Denver D.

 

[swshawaii]

Possibly a faulty PCV Elbow? VERY common problem when throwing a PO171 Code.

 

[paperman]

If you are getting lean on the banks and rough idle look into the intake gaskets. Had same issue with out trac with the 4.0. Idle would get better as engine warmed but would still toss a code. Intake gaskets are formed silicon o-ring type of gasket. Fairly straight forward change and cured the issue.

 

[jasonb1214]

changed o-rings upper & lower. now it idles fine.miss real bad and shifts funny(loss of power) t-code 0122.replaced fuel filter. (2001 sport trac). it's driving me crazy. help

 

[swshawaii]

P0122 Throttle/Petal Position Sensor/Switch A Circuit Low Input

http://www.explorerforum.com/forums/showthread.php?p=2349296

http://www.rockauto.com/catalog/moreinfo.php?pk=383029&cc=1366680