high RPM when idle

[Explorer90631]

Explorer 96 XLT v6 170k

My truck starts normal..around 1700rpm when cold and around 1000 when hot, but lately, even after I drove it several miles and the engine is hot, as soon as I set it to neutral or park, the rpm increase to 1500 rpm, and sometimes, keep fluctuating slightly from around 1400 to 1600...

Any idea in how to troubleshoot this, since I am real broke to take it a shop, would be really appreciated

 

[2000StreetRod]

IAC valve & TPS

Try cleaning the idle air control valve with throttle body cleaner. Check the throttle position sensor output voltage at idle (about 1.0 volts). Make sure that the throttle plate returns all the way to the fully closed stop.

 

[Explorer90631]

Thanks for your fast response...

I have done on a honda prelude, but I don't even know where is that valve on this truck.

By any chance, is there any place where I can get a free diagram of the engine?

 

[2000StreetRod]

IAC valve location

There is photo of an IAC valve on a later model OHV in post #4 of this thread http://www.explorerforum.com/forums/showthread.php?t=204298&highlight=iac+valve

 

[2000StreetRod]

TPS location

There is a photo of a throttle body with a throttle position sensor (TPS) in post #18 of this thread 75mm throttle body for 4.0L SOHC?
The TPS is the thing on the left with electrical connections in the last photo of the post.

 

[Explorer90631]

Thanks for the info!!!

This will be of great help!!!! I will post the results after I check both parts