: 1997 4runner idle problem


AxleIke
04-24-2008, 08:03 PM
This is a 1997 4runner, 3.4L, 5speed, and its having idle issues.

Symptoms are, upon start up, the idle sits at normal 8-900 range. Then, it will jump to 1200 ish, and back down to 800-900. Tapping the gas will stick the new idle at 1800.

Any thoughts? This truck needs to be ready to run to Moab Saturday AM. Any help would be greatly appreciated.

Thanks!

Blowntaco
04-24-2008, 08:29 PM
This is a 1997 4runner, 3.4L, 5speed, and its having idle issues.

Symptoms are, upon start up, the idle sits at normal 8-900 range. Then, it will jump to 1200 ish, and back down to 800-900. Tapping the gas will stick the new idle at 1800.

Any thoughts? This truck needs to be ready to run to Moab Saturday AM. Any help would be greatly appreciated.

Thanks!

Maybe sticky throttle plate or TPS? Just a couple ideas. Dunno without seeing the truck

AxleIke
04-24-2008, 10:24 PM
Right now, thinking this is an idle air control valve problem

Throttle body etc was recently removed and cleaned. Thinking something got hosed whilst in there.

thefatkid
04-24-2008, 10:26 PM
I've seen a couple throttle bodys worn and sticking throttle plates. Milage is around 180-220k, they were both t100s though.

Could be a IAC also, 1st startup should be over 1200rpms.

thefatkid
04-24-2008, 10:28 PM
Just seen the second post, Cleaning the IAC is usally a nail in the coffin. Those things are touchy. I would try to find a cheap used throttlebody assembly.

AxleIke
04-24-2008, 11:38 PM
oh, thats not going to make the old man happy. (his truck)...LOL.

Thanks Brian. Thanks all, good stuff. Its the old man, so he'll go new. Unlike me, he makes a shit ton o money.

RedRunnertc
04-24-2008, 11:44 PM
Vacuum leak? Like maybe something didn't get hooked up quite right?

O2 sensor wiring? (That's what was causing my erratic idle)

AxleIke
04-25-2008, 12:21 AM
Vacuum leak? Like maybe something didn't get hooked up quite right?

O2 sensor wiring? (That's what was causing my erratic idle)

Possible. Not likely though. Vacuum seems to be in order. O2 is possible. However, I've posted on lots of forums, and the IAC is a popular candidate.

Also, doesn't O2 usually throw codes?

thefatkid
04-25-2008, 09:22 AM
Yeah, don't mess up those 4 vacuum line the 5vz has :D

O2 sensors can be funny. The voltage swing and wavelenght can degrade enough to act funny but not set a code. Fuel milage is first to go when this happens.

Blown taco might have seen somthing different with TPS sensor. I have just seen them stumble on acceleration. These sensors are bad about setting a code also.

RedRunnertc
04-25-2008, 09:33 AM
Yeah, my O2 sensor was bad for a long time before throwing a code.

Denver Dave
04-25-2008, 11:34 AM
I've been fighting a similar problem for over a year.

What did you do (if anything) to start the problem?

When you push the throttle closed manually does it go back down to normal? Mine did and I attached a spring to the plenum to hold the throttle closed more tightly.

My mechanic said I needed a new throttle body and I've replaced everything associated but that. Everything is working fine for now.

AxleIke
04-25-2008, 02:42 PM
cleaned the throttle body.

That seems to have screwed the pooch.

Blowntaco
04-25-2008, 05:48 PM
cleaned the throttle body.

That seems to have screwed the pooch.

That was my first gut feeling, seen that many times

AxleIke
04-25-2008, 11:37 PM
Its fixed.

Looks like it was the IAC, but who knows. Screwed with it and it started working. Drove it a bunch, it worked. Got a spare in case it craps out.

Blowntaco
04-26-2008, 12:14 AM
Ok....so I was wrong. Damn. Glad you got it fixed:kewl: Sorry wasn't better help

AxleIke
04-26-2008, 01:35 AM
Ok....so I was wrong. Damn. Glad you got it fixed:kewl: Sorry wasn't better help

Dude! no worries. We checked all of the things you suggested. Just didn't turn out to be them. But I'm grateful for ALL the help!