Idle inconsistency (Updated, went to dealership )

[dirtyylicous]

Hey everybody.

Basically this is how it is...

Most days my car idles at 1,000-1100 rpms. During idle there is a intermittant(sp?) vibration that you can only hear in the cabin. I checked under the hood and couldnt hear or feel anything. The car is also noticably louder. It does it when the car is cold or warmed up. Also the a/c on or off makes no difference.

Sometimes but hardly ever the car idles at 780 rpm. That is where it is supposed to idle. When it idles that way the car is quiet and there is no vibration. Actually today the car was fine. But i guarantee when i go out later it will be running like crap.

I searched google and someone on the acura forums was having the same problem. He even is having a problem with a little hesitation accelerating from a stop like I am. Basically when i accelerate from a stop the car is hesitant and loud until i get the the throttle atleast half way down.

Ive done the obvious such as
Plugs, cleaned maf, cleaned throttle body (although mine has ridges on the butterfly, dont know if thats what it could be), 90k service, all fluids.

Does anyone know what could be going on? Possible know a way to idle at 780 rpm since thats when the car is acting normal lol.

If anyone has any input it will be greatly appreciated. Thanks

[wenger828]

theres is a very very good chance that this is due to a vacuum leak.. pop the hood and listen around for a hissing sou nd thats not suppose to be there.. especially check out the area of the intake manifold closest to the firewall and under the intake plenum as there are alot of vacuum hoses,switches etc there and alot of the hoses are simply just slipped onto a fitting..
i put zipties on everyone one of them so they don't come off, im also boosted to though.

edit: i didnt' read that it comes and goes away.. i think that makes it less of a vacuum leak problem (although you should definitely check and make sure all hoses are on) but probably more a faulty TPS sensor or w/e that makes that whole gizmo work

[BDR]

Derrick, you are not mistaken. vacuum leaks come and go depending on the expansion or contraction of rubber hoses due to temperature (engine temps or outside temps) As the IS300 gets older this is going to become a problem.

Dirty, can you give us a brief history of what work has been done in the engine bay? This way I can back track problematic areas. Have you installed or tampered with anything ingnition wise?

How many miles are on your car? I could be a range of things from spark plugs out of spec, to a dirty fuel filter. We need more info.

[DT2k]

check the injectors....my car does almost the same thing. I found out it was from bad o-rings from the injectors.

[wenger828]

Derrick, you are not mistaken. vacuum leaks come and go depending on the expansion or contraction of rubber hoses due to temperature (engine temps or outside temps) As the IS300 gets older this is going to become a problem.



ahh tru tru..

[dirtyylicous]

I have not moded the car in any way. The plugs are new and i even checked if they are clean. No vaccum leaks.

Someone mentioned something about messing with the ignition. Actually lexus replaced my igntion and ecu due to it locked up on me.

Yesterday the car was perect, idling perfect and nice and quiet . Today and most days it was idling at 1100 and vibrating every 3 seconds.

I also ran the bg 44k injector cleaner stuff. Helped a little with gas mileage but noting else

[Gray Rider]

This thread look familiar................

[dirtyylicous]

LOL^^^ Yea i posted in my.is first.

BTW thanks for the help gray, i will def look into that.

[Gray Rider]

It could be you need to perform an idle relearn or the ignition timing is off.








Maybe you should take it back to Lexus since they replaced the ignition & ecu. the question is how long ago did Lexus replaced these 2 items?

[dirtyylicous]

^^^They did it in august, I just cant stand their service dept and really wanna avoid them. But if its nessasary... any idea how much this will cost?

[Gray Rider]

what yr is your car?? miles?? was the replacement covered under warranty? or you paid for it??

[dirtyylicous]

I have an 01 with a little over 100k.

I was supposed to pay for it but someone on the forums that works for lexus told me to call coporate due to a problem with 01 ecus and ignitions and corporate sent me a check for the parts. I paid labor.

[Gray Rider]

You might not even have to pay for labor, there will be a initial diag fee at write up until it's determined that the items they replaced is causing the problem u are having.

[dirtyylicous]

Ill try to call and make an appointment.

Out of curiousity, how would replacing the ignition cause this problem? Im lost when it comes to most thing about cars lol.

[wenger828]

i can't imagine it causing one.. timing and stuff is preset in ecu.. not like how those cars with distributors you gotta time them with turning the cap and shit.. maybe just a mistake lexus made. if they did it, i would suggest going to them rather than trying to do something yourself

[dirtyylicous]

I called lexus and they are basically giving me the cold shoulder. They said why did i wait til now to say anything. And they said when the car left there it was fine. Also they are booked til may.

I knew this dealership was going to give me a hard time due to the Lexus corporate situation. They disliked me from the beginning. Id rather not deal with them.

If i take the car to another dealership how should i go about this? What should i say? I took the car to other places and they basically try to sell me the 90k service lol. Toyota was the best... They said my drive belt was messed up and my tb was filthy. I said thats funny... I just took care of those things. He had the most dumbest look on his face lol.

Also does anyone still know how that would cause my problem? Im just curious.

Thanks for all the help guys

[BDR]

At 100K, i would start looking at necessary changes first.... try buying two new o2 sensors from online and change both of your primary O2 sensors.

[dirtyylicous]

02's? Alright ill try it out... You say both primary's, does anyone mind telling me ezactly which ones those are?

Any other input from anyone. This has been bothering me for too long.

Thanks

[BDR]

Those are the first two you can see when you trace down your exhaust manifold. Bank1 sensor1 and Bank2 sensor1

[dirtyylicous]

Replaced the 02's today... didnt help. But, im glad i dont have to worry about them going bad anytime soon.

Today i was looking at those 2001 tsbs and noticed that there is a tsb for the lag in acceleration from a dead stop.
Maybe when they put in the new ECU they didnt update it? I dont remember having the lag before that.

If i gotta go to the dealer any way i should go about it? Tell them to check ignition timing? Tell them to reset the idle?

Thanks

[wenger828]

did you check your TB first atleast? check to see that the thingamajiggy the throttle cable connects to isn't sticking and is going full close and resting against the stop somewhere.

[dirtyylicous]

The tb cable thing looks fine. Most people say the tb doesnt go bad.
But when I cleaned the tb i noticed there were ridges on the throttle plate.

[Inspar8r]

Here's a few things to try:

pull off the black sensor (It's the TPS) on the TB and clean that. Kaptain had a problem with hesitation ,and that squared it away.

A vacuum leak may be possible, but a higher idle suggests otherwise. Nevertheless, get some carb cleaner, and start spraying around the vacuum hoses. At 100K, you're going to get some hose dry-rotting and whatnot. While spraying, pay attention for the engine to idle higher. If it does while you spray, and then drops back down, you have a leak on that hose.

Keep in mind as well that idle will jump depending on whether or not the cooling fan is running.

[kaptain86]

http://my.is/forums/f108/car-problem-fixed-334030/

as Nick said, I was having similar problems. The car was not idling right and shook a lot once it was warmed up. Take off the two screws on the TPS and clean / tighten up the screw or spring in the TPS and put it back on.

I also blew on it...must have the magic breath, or maybe it was Brandon coming and helping get it fixed..who knows

Hope you get it fixed, it sucks having to deal with that..I know first hand.

edit: thought I had answered something like this before, didn't realize it was another thread by dirty

http://www.isfanatics.com/forums/showthread.php?t=567

I'm at a loss if this didn't fix it, I described my problem in the thread above so I don't have an answer for what its doing now.

edit #2:

Ok so i took the car into my garage to check some things and clean/ tighten the tps.... And the screw is stripped!!! My heart dropped. I have no idea what to do now. The screw on top is stripped and the one on the bottom is crazy hard to get to.


I went back and reread your old thread, I caught this post. Have you not gotten to the TPS still? If so I feel it could be the answer and you need to get the stripped bolt out somehow.

[dirtyylicous]

Kaptain... actually no, i didnt get to the tps yet. Everyone mechanic i asked to unscrew said not to mess with that. It might cause serious problems.

Did you happen to have the same problem as me? Some days it would idle normal?

Thanks for your help.

[dirtyylicous]

Ok, went to the dealership on friday.

The car wasnt acting up so they couldnt do anything. Still had to pay the 118.00 for the diag fee. When i got back in my town the car was running shitty.

This sucks, I have a feeling the car will never be running smooth again. This problem is impossible to fix. They went into the ecu and couldnt find anything. I asked about ignition timing and he said it would run crappy all the time if it was.

If anyone thinks they can help me out, i will pay big money to find this problem. This is really getting to me and making me consider to sell the car. And thats something i really dont want to do.

Just a ? but, could a sticky thermostat cause this?

Thanks

[kaptain86]

Kaptain... actually no, i didnt get to the tps yet. Everyone mechanic i asked to unscrew said not to mess with that. It might cause serious problems.

Did you happen to have the same problem as me? Some days it would idle normal?

Thanks for your help.

If you read my thread that I posted you can see what problems I had, I seriously think you need to get to that TPS and get it cleaned. I had similiar symptoms with my car and after this they were gone and haven't come back since.

You are getting screwed over on dealership costs, why not try to get that screw out and cross it off the list of things to check?

[dirtyylicous]

I myself dont know how to get the screw out.

I took it to a couple of indy mechanics and all have told me that if they mess with that tps it can cause alot of damage.

Do you happen to know ezactly how to clean it to where I wont mess anything up? What do i use to clean it?

Thanks