according to my girlfriend .went to wok car was fine .after work she started car and idle was up and down like someone was stepping on pedal then releasing.i just changed the radiator now this . i could really use some advice.when i lift hood i hear a hissing vacuum from two points .the small hose off the mass air flow sensor .and the tube sticking out of the front of engine .i know they are not hooked properly any one have a diagram ...also the radiator fan sensor i unplug it and fans go on with keys on the on position does this mean that is bad .i started messing with the vacuum hose disconnected and plugged one side and surging stopped but then smoke stated coming out passenger smoke engine some type of exhaust .will pictures help ...thank you to who ever reads this and helps im a stay at home dad and when the car is not working right i stress out

 

You are going to have to take a picture if you want help on vacuum lines. Although I think her is a diagram somewhere on the car (underside of hood, maybe glovebox, maybe I'm wrong). Vac leaks will do screwy things with the idle but if it was fine with them the way they are and now it's suddenly not ok I would suggest looking elsewhere for the culprit. Could be IACV could be AFM could be TPS. I'm sure lscowboy will be bye in a bit to tell you your ecu needs a rebuild so that's a possibility also. We need a but more info to work with.

 

this site has all of the information you seek

PS - there is a vacuum hose routing diagram under the hood - look up with hood up!

 

ok no coolant leaks yeahhhhhhhh..but the surging ,i am posting a video,thanks for the advice i was begging to feel no one cared ...awwww...as i drink my 40 0z ice cold ki8ng cobra ..i read in a post somewhere timing may be ..well watch the video and then bless me with the lexus wisdom .help

 

here is the video link of symptoms

 

surging also called "hunting" has one of three causes

● vacuum leak or misrouted vacuum line (hooked up to wrong endpoints) - did you check the vacuum routing diagram mentioned earlier underneath the hood?

● idle air control valve (IACV) not working

● failing ECU capacitors


PS - did you have a look at the factory service manual where I posted a link to it in post #3 above?

 

mike, start with that vacuum leak. I'm pretty sure that's your problem. As loud as it is, should be pretty easy to find. One way to find the leak is with throttle body cleaner. Spray it around the intake and listen for the idle to change. One other thing. the clips on these old cars get brittle over time, look at all the vacuum line to make sure nothing is rubbing on the serpentine belt. hope this helps

 

first...take the Red Sox hat off and get urself a SF Giants one, also a Buster Posey jersey! shorten up that vacuum line leading to the front of the intake so it doesnt get wrapped in the clutch fan. sounds like u have a vacuum leak but its hard to tell..i would start there. good luck!

 

i took it to the shop . ill let the pros deal with it ....ill post an update soon

 

don't do that, this was an easy DIY fix

 

Check these wire!!!!! I had an almost Identical problem with mine. Turned out the clip holding these wires in place broke and the wires rubbed against the belt.

 

as far as the wire rubbing some sparking from a harness on the coil so i decided to .give up makes sense now smh

 

turns out it was the iac valve ... total cost $55 labor $55 diagnostic $80 for a used iac valve and 90 day warranty on parts and labor total damage $190.being able to go fishing again and also my girlfriend has her ride to work back priceless....




with that said .should i convert over from that manual fan clutch fan to electric ?https://www.clublexus.com/forums/ima...s/thumbsup.gif

 

dang - you have found an honest mechanic!!

IACV was my #2 prediction above

 

Like I told you in your message, seek professional help... got your car and girl back and peace of mind..