Low idle at start up.

At start up, truck wants to die until I give it some throttle. Any thoughts on what it could be?

 

Bases on that information, literally hundreds of things. Probably a throttle body issue. Pop it off and give 'er a scrub. How many miles?

 

Is this problem new or has it always been like this? Has it actually died yet or does it just feel like it will?

 

Dirty throttle body, dirty IAC valve, or bad IAV valve are the most common causes of this problem.

Mine ended up needing a new IACV.

 

Almost 400K. It has died before. It just started doing it about a month ago. IAV valve?

 

Mine was doing the same thing - I had to keep my foot on the gas to keep it from stalling, which was really hard while turning around in the driveway. I can't push the clutch, gas, and brake at the same time.

I pulled my IACV and cleaned it. It tested ok when I applied 12v, so I put it back in. The problem persisted. I finally got a new IACV and installed it, and I haven't had that problem since.

 

"IAC" valve

Idle Air Control valve. as it says, controls the air volume at idle. If you've never cleaned it, you will want to as the carbon buildup will be horrible with 400k

 

Yep. Its not just about getting 12v, there is a certain resistance its supposed to operate at.

No Start! Engine is getting spark and fuel, fried ECU?

 

Where is the IACV in this pic?

 

Anyone? I know I have to take the TB off for cleaning anyway

 

Its sticking out to the left of the throttle linkage in the first pic, the plug for it at least. You will need to remove the whole throttle body to get to it. Read the thread i gave the link for. Its not regular philips screws, they are JIS screws, they will strip if not careful.

 

here's a link to the IAC valve. runs off vacuum i think. take it apart and spray it inside the ports with carb/intake cleaner. might help.

 

It has a vacuum assist, but its completely controlled by the ECU. The OEM part is $200+, you can find aftermarket parts for around $50. If you are in LA, i found a place in Rosemead that sells the Chinese knockoff for around that much.

Just replace it, the carbon buildup is what kills this part. I posted up in my thread a comparison in ohm readings with my old broken one vs. the new one.

 

the 3.4 is slightly different than the 2.7 Caligula. It should be directly below the TB, which as you already said needs to be pulled anyway.

Jim, grab a can or two (or big can) of TB cleaner and get yourself an old toothbrush and other bristly pieces to get in the tight areas. I used a piece of coat hanger to get the buildup out of the little holes in my TB (but mine is a newer 3.4 version)

 

Yes i know, this isnt my first rodeo. Like i just said, you need to pull the throttle body, and its the same process as the 2.7, add the extra vacuum line. In either case, i still say replace it. After years of oil buildup, its not so much the valve, but the solenoid that is going to be fouled from all the crap penetrating into the module.

 

Thanks folks.

 

hey guys....
i have had this no idle occurence 2x now. once the 2002 tacoma heats up it idles fine. getting ready to clean the iac, and appreciate all the info posted here. i found this vid on utbe and it just seems so appropo to this discussion. i think this guy is onto something here, and wonder why no one has removed the iac solenoid cover and tried this twisting technique..... i am sure gonna try it.... obviouly i am lazy... but i am 65... ha ha!
wlyk
https://www.youtube.com/watch?v=WsP2-HKz7vE

/midewo

 

yeah guys!
thanks to all your (and utube's) helpful input i got off my lazy, retired, ass today and cleaned the tb & the iac on my 2002 tacoma, a 2wd, 2.4l, 5 speed, with 106K. i did this because i have had 2 episodes in the last 6 weeks that are classic iac-type scenarios...---> truck will not idle when cold, ya gotta give it gas to keep it running, then when it warms up, all is well. i had no codes / check engine light.
So since...........
- i live in so cal near disneyland, where the winters are kind of a joke...
- coupled with the fact that this problem is not very consistent (only 2x),
- and my never-have-taken-this-apart-b4 cautionary attitude
- i kinda believe in just-in-time (jit) maintenance... now as a senior
I did this with the TB mounted / on the truck. I do not regret this decision for a few reasons:
- the TB was very clean, minimal black build-up
- i did this outside, and had to finish the same day
- i needed a predictable positive first step as a confidence-builder
- this is my only vehicle
i have quite a bit of automotive experience in the last 40 yrs.... (i have only had 2 engine fires! not kidding...), the tear down was no biggie, i used minimal intake manifold cleaner, q-tips, a 9" medical hemostat/rochester to go deep (and not lose anything), toothbrushes, astrong flashlight, a vacum cleaner & some compressed air to clean up. i did notice that the cleaner pooled in the iac orifice (which on my truck is before the butterfly, facing dowm), so i made sure the q-tip came out dry before i re-assembled. the truck started on the 2nd crank, ran rough for 5 seconds...
about 4 hours, 4 cocktails....done. i went slow on purpose...
i saw the iac clearly with the ducting off, 2 screws (r they torx?????). was dying to take it off and twist the rotor to really clean, but decided to save that for next time.... if the problem persists. see the utube video link in my prev post....
it was a great day! time will tell... i do feel now i could easily move up to removing the tb, but i would want to have my usual spare car (neighbor's) lined up, more time, and a ya-gotta-do-it reason.
again thanks to all, especially to those who posted pix...

/midewo