Thanks for your responses guys.
The truck probably is running a bit smoother after throttle body and MAF
cleaning, but cleanliness wasn't the magic bullet.
The truck still wants to idle at about 1500 rpm and the trans still
shifts at way too low an rpm so that it drops below the power curve and
lugs along. It still tries its darnedest to find a comfortable gear
when going up a hill. No slipping, just constant shifting up and down.
It does drop down a gear or two quite normally if I floor the
accelerator. So there is some serious hope for a minor repair - I guess
- since so much is still OK.
> Alan Moorman@visi.com wrote in news:p8bh911h2001aqa7ccev29l2jol0bplam2@
>>On Tue, 24 May 2005 10:27:45 -0700, Joe Springer <firstname.lastname@example.org>
>>>The trans of my 98 Explorer (4WD, SOHC, 5spd AOD) is beginning to have a
>>>problem deciding which gear it wants to be in. It does a lot of up and
>>>down-shifting under either light or moderate acceleration - but, so far
>>>- only when it is thoroughly warmed up. The first few miles of the day
>>>are pretty normal.
>>>The vehicle only has 84K miles on it. I've tried to baby the trans
>>>because I've read the news group since before I bought it. I did fluid
>>>and filter changes at 30K and 60K. The fluid is currently right on the
>>>full mark, clean and not burned or discolored.
>>>At almost the same time that I first noticed these symptoms, it seemed
>>>as though the engine wouldn't idle down when stopped for a light or
>>>sign. I guessed dirty throttle body and cleaned it. Now I have a shiny
>>>clean throttle body - and a motor that doesn't idle down. Hmmm.
>>>Can this be a mild tranny failure - maybe some control device going out
>>>as opposed to a total failure? There is no apparent slippage when it is
>>>stable in a gear. That seems encouraging.
>>This is a long shot, but someone posted something similar a few weeks ago,
>>and eventually found that the Mass Air Sensor needed cleaning. (It's the
>>sensor located in the engine air intake.) Once it was cleaned, the tranny
>>response returned to normal.
>>There is a special coating on the inside of the MAS, and there is/are
>>specific cleaning recommendations.
> I believe its the throttle body coating which you are refering too. The MAFS
> is just bare aluminum on my 97. Either way, just use carb cleaner which
> states it is safe for throttle bodies and you'll be ok.
> I just squirt a little cleaner on the sensor wire, rub it very gently with a
> cotton swab and then squirt it to rinse and let it dry during reassembly. The
> darn thing has security torx screws so you either get to buy the proper
> driver or grind out the little stud with a dremel tool.
> Dunno if it'll help the tranny problem though...