Lexus082

Well, my idle speed is extremely low. The car starts shaking once it reaches the low rpms. Once I start it, it idles cold @ approx 750 rpms and then once it warms up the idle will drop down to 500-400 rpms or less. It shakes like its about to stall out but it doesn't. It will idle at the very low rpm level, but the car does shake moderately. Is there anything I should look at first or replace/clean first. I am planning on swapping out MAF sensors tomorrow. I have no check engine lights on and besides the low idle speed the car seems to drive normal. Its only when I come to a stop when the engine is completely up to operating temp. that it starts to shake due to the rpms being so low. The idle speed is steady and doesn't go up and down.

O. L. T.

iTrader: (17)

use our engine forum please. .

Lexus082

Sorry I'm used to LOC

LexusFiend

Sounds like the Idle Air Control Valve (IACV), i have this problem but havent gotten around to fixin it just yet ... try searchin for it

Lexus082

Thats what the UPS mechanic said to check/clean. He said that if it was clogged up with gunk less air could get through the valve causing a low idle speed. And if the passage way was not letting enough air in it still might not throw a CEL. I just need that gasket and I'll be cleaning mine out asap.

Gunnar

Before changing out your MAF you might try spraying the inside with electrical contact cleaner, but be sure to let it dry all the way out before you use it again.

mkorsu

Also check your throttle positioning sensor. Small changes to idle speed can be made with this.

Lexus082

If the tps sensor is say calibrated where it is postioned now, can small changes still be made to the idle speed and while still having the tps within calibrating specs? Still trying to figure out whats causing this low idle???

Lexus082

I tried to adjust the tps sensor ever so slightly clockwise to increase the idle and it jumped up to 900 rpms and then with the a/c on it went down to 750 rpms. I couldn't get anything different than 200 rpms or 900 rpms. I think something else is causing the low idle speed. Other than having the starter replaced nothing has been done to the car recently. Starter was replaced at the Toyota dealer. Car drives fine so I don't think its fuel related. Could a sensor be going bad that hasn't gone bad enough yet to trigger the check engine light but bad enough to send a slight improper reading to the ecu causing this low idle speed? Do you think the Lexus dealer would be able to pin-point this using the Lexus hand-held scanner? I never usually have any luck with the dealer and they say I need to order parts that end up not fixing the problem.