Shuttering when stopped?

Here is the run down,

Details:
-2nd gen
-reg cab
-2.7l
-5 lug
-automatic

When stopped at a stop light, my RPMs lower to around 500rpm and the truck starts to shutter. After gas is applied the shutter immediately stops and all is normal. Something to consider,I do need to replace my u-joints but I don't think that would cause a shutter when stopped?

Things I have tried:
-Cleaned throttle body
-Replaced air filter
-Checked vacuum lines
-Cleaned MAF

 

I had that happening to me if I remember correctly it was the ujoints. You may be able to fit in the tsb they just sent out about ujoints.

 

Already contacted Toyota and I don't have any outstanding TSBs for my truck, I have a feeling its the u-joints.

 

How could the U-joints cause this problem if it happens only when the vehicle is not moving? Honest question... curious...

 

I had the same problem. I cleaned the MAF sensor, the throttle body, replaced air filter, and spark plugs. All smooth now.

So, did you do the plugs too? How many miles on them?

 

Didn't do plugs. I did mine around 100,000 miles and the truck currently sits at 139,000. If the issue persists I will consider it.

I am curious to this as well. It has yet to be explained to me.

 

I don't understand how bad u-joints would cause the truck to have a low idle...if a motor idles low enough, it shutters which it sounds like that's what you're experiencing. I know that on 1st gens experiencing this problem it's usually recommended to inspect and clean your IAC (idle air control) valve.

Any check engine light codes?

 

My thoughts exactly. No codes and I will look in to the IAC as that hasn't been mentioned yet.

 

No IAC for 2nd gen 2.7l

https://www.tacomaworld.com/threads/location-of-egr-and-iac-valves-on-2-7l.422837/

 

Used any fuel injector cleaner lately?

 

I haven't used any.

 

I would try that or get the injectors cleaned if it were mine

 

Normally my idle (full temperature, in gear) is at 600 by the tachometer (4-cylinder automatic). Around once every 3-4 months it will have a slightly low idle at a stop, around 500 I guess. Seems to happen on hotter days. The low idle does cause some extra vibration in the truck cab, it is not severe but it is annoying. This is not normal but it's not really a problem or concern either because the issue quickly disappears. I do clean the TB and MAF every few years, stay on top of maintenance, and run injector cleaner every 3-4 tanks. Not sure if this is helpful but wanted to toss in.

 

My 2TR gets all weird at idle sometimes, exactly as you describe, usually only happens after a super high vacuum condition like crawling down a steep long slope in 4LO. It will idle low like 500 or just below, vibrate the truck a bit, and return to normal after a few miles or a couple engine restarts. Others have reported this issue. It's never stalled and it seems to run fine so I just let it pass and go about my business.

I posted about it here: https://www.tacomaworld.com/threads/2tr-fe-low-idle-after-steep-descent-in-4l.429933/