1998 Ford Explorer rough idle when cold

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You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs! If that doesnt do it, you may need a new idle air control valve, it's bolted to the throttlebody
The ECT(engine coolant temp) sensor will have more control over the cold idle in conjuntion with the IAT.

I will give this a try. Thank you.
verne

Let us know....

I checked for vac leaks and found none. I replaced the idle air control valve but problem persists. Engine starts, revs up and then idles way down and dies. I must work the foot feed to keep engine running until it warms up to idle on its own. Previously I had replaced the inlet air temp sensor and cleaned the Mass airflow sensor. It seems to me that this is a temperature related problem but what other sensors are temp related? Thank you.

Verne

I have a 1998 ford explore 4l sohc 6 w/60k that has the same problem. Haven't tried to fix it yet as I am mechanically challenged. In trying to diagnose the problem I read a post somewhere, not sure what site, a guy had the same problem and thinks it's the intake gasket. He said that it is possible that when it's cold the gasket shrinks causing a leak and rough idle, when it warms up it expands and no leak. I'm assuming that you warmed the vehicle up so it would idle then tried to find the leak. Sounds possible to me, but am looking for some confirmation before I try to replace it. Hoping somebody with some knowledge of this will comment.