New Problem :(

[skeemer]

This problem started about a month ago and still hasn't been fixed. One day I noticed when I first started up the car that it was idling at 750 or so (normal idle), instead of 1200-1400 for warm up. So I drove it around a little bit to see if it would warm up ok. As I drove around, every time I let my foot off the gas, the rpms would drop and it would stall out. So I took it to my mechanic and they said it was a little low on oil, they filled it back up and it was fine.

A week later it started doing it to me again. I went to get lunch on my break at work and it was fine. When I left the restaurant it started stalling out again. This time my mechanic said the throttle plate had alot of gunk built up and was sticking, which would cause sensor problems and the car to shut off. So this fixed the problem for about 2 weeks. After this, when the problem crops up again it won't stall out when I take my foot off the gas, but it idles at around 250-300.

Last Thursday the problem began agan when I was leaving for work in the morning. Took it to my mechanic and they said that the alternator was not charging the battery, so I was pretty much running on the battery when this was happening. Replaced the alternator and it was fine.

Next day it began again when I left work. Took it to my mechanic and they put a new alternator on and it was fine for a little while, then started doing it again. Mechanic thought maybe a connection somewhere, possibly in the stereo since its aftermarket, might be loose and grounding it out, and shooting out the alternator. So he checked all the fuses and connections, and replugged and cleaned all the connections. It was fine then. and over the weekend. Took it out tonight and it started doing it again.

There's no code being given. Any idea whats going on? To sum up:

1. RPMs drop to near zero when gas pedal is not depressed at all. Must give it gas when first started to keep it started, once it warms up a little bit then it will idle at around 250-300.

2. Low on oil, dirty throttle plate, and alternator have not been the cause of the problem.

My mechanic is just as puzzled as I am. I don't want to have to take this to a dealer.

Any help?

[jragosta]

There's no code being given. Any idea whats going on?  To sum up:

1.  RPMs drop to near zero when gas pedal is not depressed at all.  Must give it gas when first started to keep it started, once it warms up a little bit then it will idle at around 250-300.

2.  Low on oil, dirty throttle plate, and alternator have not been the cause of the problem.

My mechanic is just as puzzled as I am.  I don't want to have to take this to a dealer.

Any help?

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That's your problem right there. You don't want to go to a dealer, so you're stuck with a mechanic who doesn't know what he's doing.

Of the three things he tried (and charged you for), only the throttle plate would have been anywhere near the top of my list of things to try. I can't for the life of me figure out how he thought a low oil level would cause those systems. A bad alternator just might, but only under very, very unusual circumstances. A short in the stereo is truly one of the most bizarre suggestions I've ever heard.

I'm not an expert, so anything I have to say is probably not very useful. I'd be looking at things like plugged fuel injectors or a bad sensor somewhere. But your best bet is to take it to the dealer (who would undoubtedly charge you less than your quack mechanic did). Oh, and I'd go back to your mechanic and demand my money back. The guy's just throwing money at your car without having any idea what he's doing.

[SKperformance]

The oil can be a problem if it is low ,when starting cold their is alot of friction causeing alot of load which combined can cause the engine to stall

the alternator can also cause a large load causing it to stall but unlikely

Your problem goes away with you pressing the gas pedal ,so it meand you need more air to keep the engine running

sounds liek a sticking iacv

get a motorvac and make sure you iacv is working

[jragosta]

The oil can be a problem if it is low ,when starting cold their is alot of friction causeing alot of load which combined can cause the engine to stall

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While that's technically corect, that doesn't seem to explain his symptoms. He's not seeing slow cranking, he's seeing normal starting and then low idle.

I guess if the oil was almost completely empty it might account for a low idle, but if it were that low, the oil warning light would have come on.

[skeemer]

Well I dropped off the car today at our closest Lexus dealer, Lexus of Wilmington in Wilmington, DE. I didn't know I was supposed to make an appointment (never taken my car to a Lexus dealer before), so they might not get to it today. Also, I asked about a loaner but they said they only give loaners if I had bought the car from them.

Anyways, hopefully they'll be able to diagnose it. Unfortunately, the car was running normally when I dropped it off, as its been an on-again, off-again thing.

[camlex]

check rubber boot which is between throttle body and air filter. i am sure you will find broken.

[turnbowm]

skeemer,

The idle problem is quite common in Toyota and Lexus cars and is usually caused by a dirty Idle Air Control (IAC) valve. The same thing happened to my wife's 98 ES300 at 45,000 miles. Was able to take care of the problem myself.

Some dealers will clean the IAC valve and throttle body, while others replace the valve to minimize callbacks. Toyota and Lexus dealers are well acquainted with the problem.

Martin T.

[justin97]

skeemer,

The idle problem is quite common in Toyota and Lexus cars and is usually caused by a dirty Idle Air Control (IAC) valve. The same thing happened to my wife's 98 ES300 at 45,000 miles. Was able to take care of the problem myself.

Some dealers will clean the IAC valve and throttle body, while others replace the valve to minimize callbacks. Toyota and Lexus dealers are well acquainted with the problem.

Martin T.

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mine will every now and then idil really low. stalled once on a cold start. but it u rev it past 2k it then idles fine coulld my IAC be dirty and causein this? if so got any pic of where it is and how to clean it.

[SKperformance]

yes justin

try a search their are pics

turn bow he has a 92 not a 97 or newer where it is common

[ArmyofOne]

yes justin

try a search their are pics

turn bow he has a 92 not a 97 or newer where it is common

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my friends eclips did this same thing and it turned out to be a bad EGR valve.

[skeemer]

Talked to service manager at Lexus today, he said they had 2 technicians look at it and could not duplicate or diagnose any problem (the car was running fine when I brought it in unfortunately). So problem is still present I guess. I will pick up the car tonight and bring it back right away if it happens again. It would be fantastic if the problem just disappeared, but I'd always have it in the back of my mind unless it gets fixed.

[jragosta]

Talked to service manager at Lexus today, he said they had 2 technicians look at it and could not duplicate or diagnose any problem (the car was running fine when I brought it in unfortunately).  So problem is still present I guess.  I will pick up the car tonight and bring it back right away if it happens again.  It would be fantastic if the problem just disappeared, but I'd always have it in the back of my mind unless it gets fixed.

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Seems to me that the solution would be to leave the car overnight since it seems like it only happens when the engine is cold.

Even if you see the problem tomorrow, by the time you get to the dealer, the engine will be warm and the problem will go away.

[skeemer]

Talked to service manager at Lexus today, he said they had 2 technicians look at it and could not duplicate or diagnose any problem (the car was running fine when I brought it in unfortunately).  So problem is still present I guess.  I will pick up the car tonight and bring it back right away if it happens again.  It would be fantastic if the problem just disappeared, but I'd always have it in the back of my mind unless it gets fixed.

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Seems to me that the solution would be to leave the car overnight since it seems like it only happens when the engine is cold.

Even if you see the problem tomorrow, by the time you get to the dealer, the engine will be warm and the problem will go away.

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See thats the thing, the problem doesn't go away when the car warms up. Nor does it just all of a sudden appear while I'm driving. I know at startup whether or not I'm going to have the problem. If its happening when I first start, it will continue to happen until I turn the car off. If it isn't, then my trip will be fine.

I did leave it over night, but I don't know when they looked at it.