How does one reset idle for 2002 3.4L Tundra

Aloha all! Currently my Tundra does not idle and will die/shut off if pressure is not applied to the gas pedal. I changed the TPS recently as the truck was having sporadic acceleration and very low idle while stopped. Now it will not idle at all, any and all suggestions will be greatly appreciated!

 

MAF is cleaned ? butterfly flapper front-back and pivot points cleaned ? These really affect this engines (5VZ) startup and idle.

I believe idle is ECU controlled since pedal is electronic but does have a mechanical backup you see on top-front of engine.

 

Could try disconnecting battery for a few mins and reconnect - various systems will be reset by this - might work.

 

Thank you for the quick response! I will try all of the above

 

These items will help https://www.tundras.com/threads/1st-gen-lunch-table-general-discussion.60450/page-2043#post-3534928
Before performing the TB cleaning, disconnect the battery. Reconnect once completed. It will reset the ECM

 

I'd just add onto that fine post with some idiot warnings "just in case" (CYOA):

• Negative battery cable needs to remain off for at least 10 mins
• Only use products specifically labeled as "Throttle Body Cleaner" (not carb cleaner, or other solvents
• Never spray anything directly into/onto the throttle body, best to saturate a cloth and wipe
• Don't let the throttle body butterfy/flap slam shut

I may have PTSD from reading some of the stupidity I've seen over the years.

 

Mahalo (the Hawaiian word for Thank You) for all of the great tips and advice! I got the idle back to normal! Hopefully it stays that way!

 

What was the fix, for the sake of future searchers?

 

Not sure at all how it relearned it after driving it home from my mechanics shop, she did say that all the steps she tried did not work so at that point she said it was the throttle body itself and she felt I needed a new one. Driving I had to keep left foot hovering/feathering the brake so that the truck wouldn’t die off. Het the truck home, removed everything connected to the throttle body in order to look for a part #, also removed the TPS because the wiring connection was not cooperating with my attempt at removing it. Removed both of the 12mm bolts and nuts holding the body and slid the unit forward, I didn’t want to remove it completely as i didn’t want to mess with the hose connected to the bottom. Since I couldn’t see any type of part number, I replaced everything.
This morning I drove the truck to our neighborhood convenience center to off load some trash that was in the bed, while waiting in line, I took my foot of of the accelerator and low and behold it held idle! Needless to say I was very happy! Drove around a bit and it works like a charm! So like i said, I cannot point to a particular point where I can say this is what fixed it, could have been removing and replacing the TPS, could have been the drive to the convenience center etc, I’m just glad it’s working!

 

Any time you remove the battery cable to work on the truck for more than 10 minutes, it resets the ECU, forcing it into re-learn mode. It's not uncommon to experience rough idle until the ECU dials in its parameters, and completes relearn. We've seen it frequently.

Relearn will go with a baseline set of parameters. Say you've got a little 1mm buildup on your throttle body, which won't allow the throttle plate to close to the brand-new level. The ECU has to correct for that position change. Say your upstream O2/AFR sensors are older and maybe not as accurate, so the ECU can't truly see what your air/fuel combustion mixture is exactly, it's got to adjust around that. Say your MAF has never been cleaned and is coated with film, because you're ignorantly running a cold air intake and/or an oiled filter, which will cover your MAF sensor in a light film of oil, affecting the accuracy of its reading, the ECU has to learn how to adjust around that.

There's a ton of variables involved there, and a lot of ways it can go wrong. The best thing to do is (A) any time you make changes to something that touches on air/spark/fuel, always unplug the negative battery cable so the ECU can reset, and (B) any time you need to reset, that's the time to clean/adjust anything that deals with air/spark/fuel, and (C) if things run rough after a reset, best to idle it out, go on a short local drive, help the ECU re-orient itself again.

 

Thanks Shifty! That’s a ton of great information! I was thinking of cleaning the MAS, throttle body
etc and will now be doing so following the steps I’ve learned in this forum.

 

These guys are your friends. Some places actually sell them together as a kit. Highly recommend, CRC products are awesome. Doesn't matter whether you need contact cleaner or brake squeal silencer, I've found CRC branded products always work above average. Don't mix-and-match or use anything other than the correct cleaner for the part.

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My Wally World sells this as a combo pack in a smaller (one TB cleaning) size can... I think the same oz sizes as what's pictured. It may be as close as your nearest Walmart.

 

Agreed - This is the Only thing to use.

 

What is the recommended frequency for cleaning the throttle body?

 

Ultimately, when it’s dirty. No easier way to put it.

It can get dirtier faster if you do unwise things like … using oiled filters, using aftermarket air intakes, using less restrictive filters, and probably a handful of other things. Generally speaking, it’s something I’d be checking now if you never have, and if you have cleaned it, I’d be checking every 20k-30k miles. If you are using an oiled aftermarket filter, I’d stop, but if you insist on not stopping, I’d probably be checking and cleaning 2x-3x more often.