HELP!!!When cold, i start it and it revs real high then will die - is it O2 sensor??

[msbones]

I have a 1998 Explorer 4WD. When I start it in the morning when it is about 40 degrees out it will rev really high and then go way down and it dies. Then if it doesn't die it will act like it and then rev way up again. It will do this until it is warmed up. What could it be? an O2 Sensor? If so, isn't there three O2 sensors and which one would it be? Thanks so much to everyone that reads this

 

[Alec]

O2 sensors usually don't lead to startup problems.

I'm thinking IAC more likely. Do you have the HVAC system on?

 

[msbones]

No, the heater control is off and it usually doesn't matter if I have the fan on or not on either vent or air.

 

[aldive]

Originally posted by Alec
O2 sensors usually don't lead to startup problems.

Oh but they can; been there done that,,,,

Dead Link Removed

 

[Alec]

Notice how I said "usually".

 

[Billy177]

it is your maf, clean it.

 

[Brandons]

i wouldnt be able to say its the maf, that shouldnt cause the almost dieing/dieing problems, i know my maf had a good layer of black on it, and most cars run faster when started in the cold to heat up i figure. You can unplug the maf and try it then, if theres no difference its not the maf. Hell the maf cleaning is the most usless thing ive heard on this site, did nothing for me.

 

[Billy177]

do you have teh sohc because then you have the notorious intake manifold leak

 

[Brandons]

92 explorers dont come with sohc

*EDIT* scratch that, i was looking at his name stuff, said 92, might wanna change that bones

 

[TPLYNCH]

I second Billy... If you have the SOHC engine, and you haven't had the Intake Manifold O-rings replaced (owner notification program 00M12), then that is probably the problem. You have described the classic symptoms.

 

[expobronc]

bones... where in iowa?? Clear Lake here

 

[msbones]

Ames, Iowa