Hey there, Hope somebody can relate. I have a 2000 tacoma 4x4, 3.4L, 5speed, with 102, 000 miles. AWSOME truck. Have only replaced a batterie, and PS pump. But anyways it just reciently started idleing high not only when cold but when Im driving at any speed Ill push in clutch to shift and truck will run at 2000 RPM !!, If I pull over and wait about 15 seconds the RPMs will drop to 900, I can rev the engine while stopped and it will keep returning to 900RPMs. Ill take off to drive and right back up to 2000RPMs.
Ive heared about cleaning of throtle body??
PS. The truck has a throttle body spacer, and K/N cold air intake (not a new addition)
Well I just drove the truck, heres how it goes. Starts good, I let it warm up (Its like 20 degrees out), I drive it and the temp gets to be about half, Now for the funny part: The 2000RPM idle only happens when ground speed is over 20mph, Ill push in the clutch and let the truck roll, and as long as im doing anything over 20mph she runs 2000RPM, the second I hit 19mph, RPMs drop to 1100 (which still seems high to me, I dont know) . Now the issue is intermitten as for I stopped for gas and left and it didnt do it again.
No linkage binding
No check engine light
No abnormal noise
No history of any electronic issues
I havent changed the timming belt yet, nor have I had the valves adjusted
Iv never changed any O2 sensors
I am original owner
Hmmm....You got me thinking really hard.
The whole 20mph thing is throwin me for a loop.
It needs the extra air allow for the higher idle, and if your not opening the throttle and the linkage isn't binding allowing it to stay open.
Then the only other way it could get air is from the IAC.
Or a vacuum leak but that doesn't fit the issues.
I don't suppose you have access to a scan tool?
__________________
"The glass isnt half empty or half full...
its twice as tall as it needs to be"
~How an engineer views life
Duh, I fell kinda dumb, because I think 20 mph is when the cruse control becomes active, I unplugged the harness on the cruse unit, and it never acted up the whole 4 hr ride home.
When it was acting up, the cruse was never on (ie, light in dash, and the light does work) Hum..
Now my question is If there is a recall for the cruse control on the 2000 Tacoma, Iv been looking and Iv only found people having issues with there 95-and 96s
More issues. I unplugged the cruse control unit. Thought it fixed it, drove 300 miles, and check engine light came on. So I plugged the unit in, and disconnected the cable. All was well, I took some sugustens from here, and cleaned throttle body, and MAF sensor. NOTE (improved 2 MPG)
Drove another 600 miles and idle started jumping from 900-1700 RPM irratically by itself, when truck was warm, this only happened once, and it lasted for about 5 minutes and stopped.
IAC valve? Any tests on this $300 part?
Thanks for all the great feedback, I will spreed the good word!!!!!
have you checked for vacuum leaks yet? I'm thinking the IAC is working if it can change the idle like it is. So it must be an input causing the IAC to change as it is. You already cleaned the MAF, so that probobly isn't it. Give the engine bay a good inspection, check all the vacuum lines for possible leaks. Also, any check engine light now?
__________________
"The glass isnt half empty or half full...
its twice as tall as it needs to be"
~How an engineer views life
Nope no check engine light. I have checked for vacuume leaks, but i will further investigate, PCV is functional. Also, last week The truck wouldnt idle high on start up. (Its like 10 degrees out). It idles high on start up now, and hasn't had the (loop) for a couple days now.
Well its kinda hard to test a TPS with a multimeter, the best thing to use is an Osiliscope. A meter doesn't refresh fast enough and an Oscope you can see a picture of the voltage change.
__________________
"The glass isnt half empty or half full...
its twice as tall as it needs to be"
~How an engineer views life
High idle (HOT)
Linear Mode
