rough idle in the morning | Ford Explorer Forums - Serious Explorations

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rough idle in the morning


May 2, 2002
Reaction score
City, State
so cal, calf
Year, Model & Trim Level
2000 prerunner
ok i need help i am at a loss for ideas of what to do. i did a search but couldnt find a thread on what is happening to my truck. after my truck sits over night and i go to start it, it immediately idles rough and seems to stumble. it holds at about 1000 rpm but is not smooth at all. after about 10-20 seconds it smooths out and is fine until the next day when i start it again. this truck is used offroad alot and in dusty conditions so i tried cleaning the mas air sensor and the iac but it didnt help any. i read some threads about the ECT and the thermostat so i went ahead and changed both of those but there was no improvment. i pulled the code yesterday and nothing came up. i am going to try changing the plugs next, does this sound like a logical step?

2000 ford ranger, 44,000 miles, 4.0 auto.

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mine does the same thing and plugs and wires didnt do the trick not to say it wont on yours im thinking its the iac or o2 sensors

IAC and changing the plugs would be a good idea if you haven't changed them in a long time. You can get a new IAC on for about $50.

would a bad iac or o2 sensor throw a code?

not all the time also check or change the temp sensor for the computer