Hello, I own a 93 ranger splash 3.0 and have about 108,000 miles on it. I love my truck and I have had no major problems, but one.
Every time I start my truck, when the engine is not already warm, the idle revs and then slows by itself. I have to step on the gas for about a minute just to keep it running. Its really annoying and I have taken it to a couple of garages and they have not really done anything. One cleaned the throttle plate but that did nothing. Once the engine warms up the problem goes away. That is what confuses everyone the most. I have had this problem for about 2 years. I only have this problem before the engine heats up. If I just let it warm up with out driving it, its takes about 15 minutes before the idle stays the at the same RPM. I dont have a tachometer so I cant tell you the RPM its running at. Maybe its just an idle problem or could it be electrical? Not the right air to fuel mixture? I dont know what to do to get rid of this problem. Some please help me. Any useful information would be helpful. Thanks

 

sounds like you have a sticking IAC. (idle air control valve) Located at the throttle body. That would be my best guess.

 

Welcome to FTE Hirschberg!

I agree, sounds like your IAC valve. A few people have had luck taking it off and cleaning it, but most times when it fails it needs to be replaced. Easy job, unplug the harness connector and unscrew the two bolts securing it to the TB assembly ...installation is reverse of removal. Looks something like this:

 

Thanks for your ideas but the IAC is working fine. I read in my chiltons that if you unplug the IAC your rpms will reduce and your engine will almost stall. When I unplugged it, it solved the reving and slowing of the engine but the idle was very rough, and almost stalled. If that happens, the book said the IAC is working. I also ran a Ohm test and it read no Ohms. The book said it should read between 6 and 10 Ohms. Maybe I was reading the multi-meter wrong. So before I spend 50 bucks on a new IAC, I should probably get a computer diagonstic test done.,right? Another thing is that I could not even find the right IAC. The electical plug on my truck comes off the end of the IAC at a 90 degree angle. The ones at the auto store came off the straight off like the one in the picture. My wire would not reach the plug if I bought the one at the auto store. Thanks for your tips and let me know if its a good idea to go and get a computer diagonstic test, if I dont really have too.

 

The IAC can "test out" fine like that but still be dirty inside, causing the valve to stick.

You might also think about cleaning your MAF sensor.

Checking to see if your computer has any stored trouble codes is a good idea, and is something you can do yourself for free:

http://www.dalidesign.com/hbook/eectest.html

or

https://www.ford-trucks.com/lc/lc.ph...iew/Tt4Q98.PDF

 

mine did the same thing and it was the Idle air control valve. Any of your buddies have a 3.0? It just takes a few minutes to change out and you could test it that way. OR, you could buy a new one-and fix it--and write chiltons a letter.

 

you need to replace or clean the Air charge temperature sensor located between injectors 3 and 4 on V8 and maybe on V6 check that out it gums out be carefull not to touch the middle part its very sensitive
http://www.smpcorp.com/mycgi/ibg.asp?parts=AX3

 

my 93 splash ranger is rabbid it revs from 700 rpm to 1800 rpm when it is cold if i disconect the IAC it quts surging and runs at 600 RPM and I have no codes any ideas?