Hey guys
Have a 1990 4runner with the 3vze and have issues with the idle.
It seems to struggle to keep the revs up often after stopping at traffic lights, or when turning with the wheel at full lock.
It also has a bit of a stutter at around 2000rpm in 4th gear, is quite jerky.
Replaced so far:
Dizzy cap and rotor
Plugs
Leads
2 x Solenoids under inlet manifold on right side of vehicle(they were missing when i bought the truck)
Other things ive checked:
Throttle body removed, cleaned and replaced
Idle screw changed but does nothing
Vacuum lines checked (1 is open not sure why or what its for)
I was talking to my auto electrician today when i got my AC regassed, and he says there is a sucking sound coming from the EGR thingy on the right hand side of the engine which shouldnt be there.
This is it:

There are some holes in the bottom of it that are constantly sucking in fresh air and its quite loud.
Had someone else mention that it might be only running on 5 cylinders?
Anyone have any idea on what mite be causing my screwed up idle?
Cheers

 

I think you are missing the EGR Temp Sensor! Is there a small 4 wire harness with a grey plug on it that is laying on the right fender well area somewhere? The temp sensor threads into that little hole where the sucking noise is.

 

Early non-California 3vz's did not have a temp sensor but the EGR still had the threaded hole. The hole doesn't go all the way through though and won't cause a vacuum leak. Your description sounds like the diaphragm in the valve has failed, creating a vacuum leak.

 

I'm having the same problem. bugs1961 might be right. Let me know if you find a fix.

 

What is the vacuum line that is disconnected?

Check the vacuum lines that come from that EGR as well.

 

agree with bugs, the EGR valve inside is broken if those holes are sucking in air.

 

(maybe this is no help at all) mine has that same peice missing and there is no leak or vaccum sound threw that hole.

 

A vacuum leak test might help you figure out whether that's the cause of your idle problems. Be careful spraying flammable stuff around hot exhaust pipes.

Also what's that crud around the pipe that joins the EGR valve from the left (top in the pic)? Right where it joins the EGR valve? Not some jury-rigged attempt by the last mechanic at fixing something broken? Here's a clean one:

https://www.yotatech.com/forums/f16/...-needed-69984/

 

well just my 02 cents....the VAFM has a Idle Air Sensor that could be going bad and not sending the correct signals to the ecu, and not even throw a code if it does it intermittently

this could cause rough idle and a hessitation when accelerating or under a load and jerking

just something to check into