Sometimes when I am at a stop light my engine will fluctuate in idle speeds. It will sound like it is going up and down and up and down and up and down....you get the idea. Sometimes if I press on the pedal it will slap some sense into it. But that doesn't work all the time. Any Idea what I should look for or fix?

It's and 89 22re 5spd 4runner

Thanks.

 

Not sure if your rig comes with one, but could it be a sticky or dirty throttle body and butterfly valve, dirty injectors or fuel filter? Check these things out first. I'm sure other members will gladly chime in with their opinions. Hope mine will get you started on the right track.

 

After you are sure all the tune-up items have been taken care of, check for vacuum leaks and the TPS for proper operation.

 

Where and what is the butterfly valve. And How do I check the throttle position sensor???

I run fuel injection cleaner everytime I change my oil, so I imagine that they are clean.

I've been meaning to change my fuel filter and fuel sock so maybe those are factors.

 

This should help you a bit:

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

Do you hear any vacuum hissing?

Does it do it only when at idle when warm?

Last time you did a full tune up?

Was it dry outside?

 

I honestly don't hear any hissing, it does happen when the engine has been on for a while. A week ago I did my plugs wire cap rotor, oil change and coolant flush. Thanks for the link 96 runner

 

In that case, I would check for any error codes. It would most likely be the TPS that need adjusting or replacing, but more likely adjusting.

 

I'm Pretty New To Yotas, How Do I Check For Codes. There Are Absolutely No Readouts In My Dash.

 

Taken from pirate FAQ ( http://www.pirate4x4.com/forum/showt...=173918&page=1 )




EFI System – Trouble codes



Toyota EFI trouble codes see: http://www.off-road.com/toyota/tech/codes/

How to read the codes?
1. turn ignition on, but don't start the engine
2. short the check engine connector (or between T and ground)
3. check engine light will now blink indicating the code. Count the
number of successive blinks and that's the code. Be aware that there may be more than one trouble code stored, in which case the next displayed code is different. There is a 3 second pause between the codes. Codes will be repeated until you remove the short in check engine connector.
4. Clear the codes by removing the "stop" fuse, or disconnect the battery for at least 30 seconds.

 

Autozone will read codes for free. At least they did before. Even if you do not have a CEL, you may still have a code stored.

 

both of mine do the same thing if the timing gets off a little. I put the timing light on it to correct the problem. works for me, might for you too.

 

Check codes with a paper clip across the check connector, its kinda between the coil and the airbox. Its the one with only 2 connections.

Think your TPS need help.

 

Last time my idle was acting up, it turned out to be that the idle was turned up too high and the computer would try to bring it down and they would fight over the correct position causing the rpm needle to jump between 2k and 13k. Solution, lower idle speed.

 

My V6 did that - everyone thought I wanted to race!
It was a cracked throttle body so I replaced it with a 'previously used' unit - end of problem.

 

Same answer here. Quickest easiest thing to check. Adjust the idle down a notch and see if it goes away. Fixes it in a jiffy

Does the idle only fluctuate when sitting still with your foot on the brake? Try sitting still at idle with foot off of the brake, and then put your foot on the brake and see if it starts to flucuate. If so adjust the idle down, put foot on brake and repeate untli it stops doing it.