Bad Shake at Idle When Warmed Up 2.4L **UPDATE POST 16**

So I have read many threads about when sitting at a stop light in drive and no air conditioning on, there tends to be a rough idle on the 2.4L. To the point that the steering wheel shakes and the hood shakes really bad. I am having the same issue.
No CEL codes, Throttle body has been cleaned, IAC has been cleaned, voltage checked on TPS, intake temp sensor has been changed, coolant temp sensor has been changed, new plugs, wires, cap and rotor; pretty much everything gone over. The truck has 160K miles on it and the only other thing I can think of are the valves being too tight. I take the truck in next wed. to have the valves checked and possibly new pucks installed if needed. Luckily, I wont have to do an exhaust valve job. I checked my compression and all four cylinders are between 150-160psi.
Can anyone else who has experience this issue share your insight on the subject? I will post my findings after my appointment.

 

It could be bad motor mounts or just post a video

 

What is your RPM during the rough idle? If it is really low, then that is why its rough.

 

Motor mounts are fine and the tranny mount is fine. It idles low, around 550. When you turn on the A/C or the choke is on in the morning and the idle goes up between 750 and 900 then the idle flattens out and is as smooth as can be.

 

The idle being too low must be why it is so rough. So, now you have to figure out why the idle is so low. The idle is controlled by the computer, based on what the sensors are telling it. So either the ECM is bad, a sensor is bad, or a wire from a sensor is broken.

 

Got the truck back, 3 valves were tight; down around 7. Got them back up to 13 where they should be. Rough idle is still there. Talking to the tech, he says that the 4cyl with an auto trans tends to have a shake at idle. He says its the nature of the beast and only does it with that combo. They checked out anything else they could think of idle related and everything checked out on the up and up. At least its good to know that the valve train is back to where it needs to be for another 150,000 miles

 

it still shouldn't wiggle at idle in gear, you have drive by wire, so there should be some set screw that can be adjusted to bring the idle into spec...

 

You arent supposed to be adjusting the screw because then the idle will be really high when the A/C is on or when the choke is on when its cold

 

Choke? There is no choke. Hasn't been one on a Toyota for 27 years .
Idle speed is controlled by the ECM and IAC (via increasing fuel and/or air).

 

Sorry, technical nazi, ill be more specific in the future. Different method, same result. I was just pointing out that you cant raise the idle with the set screw. It may not have a choke but the IAC and ECM set the idle as if it did have a choke to get the higher idle when the engine is cold. Sheesh

 

sometimes, depending on the age of the vehicle, the set screw has to be readjusted to get it all back to ''normal', wear and tear for years of operation......and, regarding the idle, the set screw should adjust the idle as it 'sets' the baffle in the throttle body....

instead of fighting it, give it a try, you can always put it back to where it was before if it don't workie...

 

On the 22RE the idle adjust is a large screw at the throttle body do not adjust the throttle stop that's not what it is for. Your problem most likely a vacuum leak those engines idled just fine it is not normal. Get some thing that burns like carb cleaner and spray it around the hoses and joints if the idle picks up you have found your leak. There are 3 idle kicks cold engine, power steering, and A/C but the base idle is adjusted by the large screw on the throttle body only.

 

vacuum leaks was one of the first things I checked for, not a single

 

The earlier engines had a tendency to leak at the #4 cylinder around the intake gasket. Try pulling plug wires one at a time while idling and see if one makes little difference then go after that cylinder. If it's high mileage you could have an injector issue with a poor spray pattern.

 

Top end was just gone through and intake was cleaned when they checked the valves. No leaks at intake. Shop checked for any other leaks while they were in there. They also rechecked the voltage on the TPS and it was dead on. They also checked the motor mounts again and the tranny mount and they were fine. This shake seems to be a gremlin that has come up many, many, many times on this forum and on others and no one has been able to pin point it yet.

 

***UPDATE*** My idle is now perfect when the engine is hot while sitting at a stop light and I have a theory as to what happened.
At idle, the set screw on the throttle body which is set at the factory makes contact with the round butterfly arm that the throttle cable is attached to. I went to my local Toyota dealer, who had a complete throttle body in stock and i looked at that set screw. On the end of the set screw where it makes contact with the round butterfly arm there is a ridge from where they cut the edge down during manufacturing. Looking at my set screw, this ridge has been worn down from vibration and constant contact with the round butterfly arm over the years. There is even an indentation in the round butterfly arm where the set screw comes in contact with it.
By wearing down it allows the butterfly to close just slightly more then where it was set at the factory, hence lowering the idle a couple hundred RPM. I loosened the nut on the set screw and turned the set screw no more than about a 1/4 turn to make up the difference for this wear. Sure enough im sitting back at 750 RPM at idle when stopped in gear. I took the truck for a spin and sitting at the stop light, warmed up; it never dropped below 750.

 

pictures please

what screw are you talking about? is it the one in front for that fast idle actuator thingy?

 

Its the throttle stop set screw. I didnt touch the one for the fast idle actuator

 

The one on the throttle body is adjusted for clearance there is a setting measurement I don't remember what is was. It keeps the throttle plate from sticking in the bore. I don't doubt that your idle went up but that is not for idle adjustment. On the 2.4 there is a large screw behind the throttle body that is where the idle adjustment is made it is an air adjustment just for idle.

 

Does the 2.7 have this as well??