truck idling high

I have noticed that my truck has been idling pretty high when cold, which I know is what it is supposed to do but it is idling in the 1700-2000 range for a little bit before it settles. To me, it should not be in the 2000 range for cold idle. My other 2 tacomas have idled in the 1200-1400 range for cold then settled to 80-1000 once warmed up. Any thoughts on this?

 

Reset the ECU by disconnect the battery and letting it sit for 30 mins.

then see how it runs.

Mine was idling high and after resetting the ECU it was fine.

If that doesn't fix it it may be your Idle air control valve or your throttle position sensor.

 

From my experience with bad idle here is a brief list of items to check:
-TPS
- ECT
-MAF
-Vac Leaks
- PCV valve
- IAC
- throttle body functionality
- Throttle cable
- Dashpot
- idle screw
- O2 sensors
- Engine Timing
- Air filter
- Spark plugs, dist cap, wires etc.

 

I reset my ECU and nothing different. How would I go about checking the TPS, MAF or any of those at the top of the list? I checked my throttle cable and it looks good and there is no pressure when it is in resting position. My air filter isn't real dirty and the spark plugs were changed within the last 15-20k. When I first start in being cold, it sits at about 1700-1800 for 30seconds or so then starts to go down but even at warm running temp, I can cruise at about 10 mph without any throttle.

 

I have a cold weather package on mine. Mine when it cold say 40 or colder mine start and runs high idle 2500 till the engine starts to warm up. Its that way to get the O2 sensors up to temp fast. As the temp goes up the idle goes down. it will drop down the 700 rpm range when the engine is fully warm.

Sounds like you have a cold weather package on it.

 

Well mine never really drops below 1k though which shouldn't be should it? When I first test drove it, i though it had died at a stop light because it was running at about 700 and I couldn't even tell it was running lol

 

Low idle is 750 and high idle is around 1000.

So yes, it should drop to below 1000 rpms.

 

Yea I figured. any help with my above post of how to test TPS or any of that?

 

Search (ctrl-F) and looks for the TPS, there should be a testing procedure using a multimeter.

 

our throttle bodies wear all the time. try moving the throttle butterfly side to side, mess with the part where the cables attach. if ur idle moves down to correct level then the throttle body bushings are worn. it allows the butterfly to slide side to side nd jam above idle. if this is the case find a known good throttle body

 

My TPS tested good. But was still acting up. I changed it and it helped. I also twisted it all the way around too.

High idle is a frustrating problem to solve unless its something obvious.

Try this:
1) try kicking your accelerator to see if the idle comes down. I dont mean rev it I mean kick it.
2) With the hood open, try to push back really hard on your throttle body butterfly valve lever. Push the opposite way of what opens it up nice and firm. If it drops off your throttle body could be losing some funcitonality. There is a little spacer in there which when wears doesnt allow it to close fully.

 

I just got my truck out of service and the tech noticed a high idle in my truck. I forgot what he said exactly but he mentioned worn spark plugs were the cause. I'm still on my first set and haven't changed them out yet so that's on my list to get done.

 

Ok, well I played with the throttle body/butterfly valve and it didn't drop my idle at all. I am still idling at like 1100-1200 once fully warm and that puts me at about 15mph without touching the throttle. I am going to check the TPS and go from there

 

Could it be a bad thermostat?

 

from personal experience on 90s vehicles, vacuum leaks almost always cause the high idle, id start there its the cheapest fix. just look around for cracked, broken, or kinked lines. try cleaning the throttle body and MAF sensor

 

I will look into it because it really started doing it after I detailed the engine bay so I may have knocked something loose. Is there another sequence of checking for vacuum leaks if I do not find anything?

 

Would expect some high temperature problems with that one.

 

Agreed. Vacuum leaks are everywhere on the older trucks - like mine. Sometimes they're too small to find with propane or throttle cleaner spray method.

 

Replacing all of the vac lines and plastic connectors is cheap and easy way to solve vac leaks, instead of hunting them. Replace your PCV valve as well.
Clean MAF, Throttle body, and IAC valve. Cleaning the IAC will only fix the problem for a short time, if it is the cause.
The intake air temp sensor and engine coolant temp sensor can cause high idle if their readings are off. They tend to give erratic readings before they fail. Check their readings with a multimeter.
As with all problems, test before replacing sensors. Your wallet will thank you.

 

Where is the best/ cheapest place to get new vacuum hose if I wanted it a different color? Or if they just have it in black where is the best place to find it cheap. Thanks for all the help guys! I will be traveling for the next month but when I am back, I will be spending quite a bit of time working on my truck.