97 Ranger w/ 4.0L V-6 idle problem...PLEASE help!!! - Ford Forums

morgan70 · 12-28-2007, 17:49

I have a 97' Ford Ranger w/ 143,000 miles. My problem is when in drive, and stopped, the idle goes from 1,000 rpm to 600 rpm and back up to 1,000 rpm over and over again, and sometimes even shuts off. It will restart with ease. I replaced the throttle control sensor. What else can I do? Thank you in advance for any help!

ranger_guy_82 · 12-28-2007, 17:58

I also have a 97 with the 4.0 and about 148k...Im tellin u right now it could be a number of things...Vacuum Leak, The Idle Air Control valve, intake gaskets, fuel filter, carbon buildup...Dirty Mass Airflow Sensor....Most likely the IAC valve is faulty or plugged up with carbon....Take it off and clean it out with carb cleaner...make sure to move the plunger up and down and then give it a coat of WD-40 inside...Try that first and let us know if that helps....If not, u should clean the MAF Sensor with Electronics cleaner....well u should do that anyways at least once every 6 months to a year...

morgan70 · 12-28-2007, 18:09

First of all let me go ahead a say how great the fourm is. Who would have thought that one could retrive as much information from on site.

Next thing is I replaced the fuel filter about 2 weeks ago due to another problem.

I replaced the throttle control sensor about 6 months ago. I guess I should tell ya'll that this has been an on going problem for about a year now.

Thanks again for everything, I am totally grateful.

dcsnypa · 12-29-2007, 16:18

I would defnently take that IAC off it should look somthing like this

IAC Cleaning Idle Air Control Maintenance

just take it clean it and put it back on mine was doing the same thing as your truck but as soon as i got it cleaned its never better

mhein · 01-02-2008, 10:00

Hey Morgan,
Having had the same problem a few years ago, I know it's the IAC. They're rather infamous for failing in this manner.
It'll cost you about $40 for a replacement... one wiring plug and 2 bolts are all you'll that need to fiddle with- a 5 minute job.
BTW, be SURE to use an OEM brand. Do a Google search of "cheap auto parts" to find a reasonable price. Many on-line stores will include free shipping with orders of $50 or more, so get a new fuel and/or air filter(s) while your there. These filters are often overlooked in "tune-ups" and they can cause big troubles. Especially the fuel filters- they become plugged even partially and you're looking at a replacement of the fuel pump (in the Fuel Tank) in the not too distant future. Since the tank itself must be dropped, if you have a qualified mechanic do it... BIG BUCKS!!!
Take care... Mark

morgan70 · 01-02-2008, 15:00

Thanks everyone for the info. It was the MAF sensor. I actually changed the fuel pump about a week ago. I fond that removing the truck bed proved far easier than dropping the tank. Anyways thanks for everything I could'nt be more grateful to everyone that helped.

mmcfly · 05-12-2008, 14:58

i am having the same problem, when stopped in my 98 ranger it bounces back and forth between 600 and 1100 revs, it causes the whole truck to jut, and you can hear a click, which i can see is the A/C rotar starting and stipping.... it is fine when driving. i have replaced the fuel filter. one thing i have noticed is that it only occurs when i have the a/c or heating on in the truck. it idles completely fine when i have it set to off.
i'll look into those other things mentioned, but any other thoughts considering the whole a/c involvement in it???

thanks for any help.