Hi,
My 96 T100 5spd (just bought about 2 months ago) generally idles at between 1500 and 2000rpm. If I slam the gas pedal and take my foot off quickly, the idle drops to about 800rpm(about right). I have taken out the throttle body to clean it twice, and have made sure that there are no set screws improperly adjusted. When the idle is stuck high, I am able to see a small space between all 3 set screws and their contact points on the TB, so I know its not them. I find that if I twist the TB spindle (whatever you call the axis that the cables attach to) by hand with a bit of force, I can make it idle down to a reasonable rpm. I used some light oil on the spindle, in case there was some friction that was impeding the spindle resetting to the right position. That worked for a couple of days, but the problem is back! Any suggestions? Do I have to take apart the spindle and springs and everythign? Could it be the other end of the spindle from the cables, I think its called the TPS?
Thanks for helping out a new owner and new Yotatech member
Tomas
P.S. In trying to find other threads about this problem, I came across the term MAF. What does that stand for?

 

Hey man.. it sounds like you are havein the same problem i did.. it could possible be the throttle position sensor.. it is a little green colored box. It is a common problem at going out on our trucks.. you can take a screwdriver or something and tap on it a little bit and that might fix it for a while if not.. it most likely needs to be replaced..

 

Sounds like you have the same problem I have after wheeling in deep water. What happens to my truck is that I will get some water on the airfilter and it allows airfilter fibers, dirt, and water to then pass in to your engine. The parts that do get in are very small and won't cause any internal damage, but...
They do get on the mass air density sensor. When this gets dirty it caused the exact same thing to happen to my truck. There is a quick and cheap fix though.

Go out and get a bottle of electrical contact cleaner. Take your airfilter out, disconnect the mass air density sensor (it has about 5 wires going to it and it is located on the top side of the airfilter housing), remove the housing with the mass air density sensor. Now there should be two 10mm bolts holding the mass air density sensor on. Take those off and look into the inlet side of the mass air density sensor. You will see something that looks like a missile. If you look deep down inside of there you will see two wires. You need to clean those. Spray the wires with the electrical contact cleaner and let them soak. repeat a few times. Reinstall everything after you give the wires some time to dry. It should idle normal. Sorry this is so long

Andrew

 

Thanks 95superchargedT-100 and BigA! I'll try the screwdriver tapping, then the MADS and then maybe the TPS replacement. I appreciate your help.

If anyone else has other suggestions, please keep replying to my post. I'll try some of these options and post their effectiveness.

 

The MAF is the Mass Air Flow sensor. I have not heard it called a mass air density sensor since it measures flow of air accross it, not the density of air. The density would change with elevation but that would be adjusted for by your O2 sensors when the sense too rich a mixture of fuel.

Look at http://www.4x4wire.com/toyota/mainte...tenancep5.html for the cleaning proceudre

 

I work at a Toyota dealer in parts so I see alot of this. My #1 guess is the TPS. Good luck!

 

Well its been a while, but I finally took the truck to the toyota dealer. The mechanic there said that the high revving is due to worn bushings in the throttle body spindle. The only solution is to replace the throttle body.
So now i'm looking for a good option for a new (to me) throttle body. Does anyone know where I might find a used one, or a remanufactured one? Maybe from a wrecker? I've been told that the throttle body from a tacoma 4x4 with the 3.4 v6 will fit my truck. Any comments?
thanks for all the input and advice.

 

I hope that its not too late and you didn't buy a TB.
I had the same problem and all I did was add an extra return spring on the TB and problem fixed. Make sure you don’t get one that’s too tight or your gas pedal will be hard to push in.

Cheers
Matt

email me if you have any other questions

 

I don't mean to revive an old post but can you tell me what or where I can get the extra spring that you add to the TB?. I have the same problem. Thank you