Can A Maf Sensor Effect Idle?

[kelvin6]

Well I joined this forum to repair my co-worker's 98 ES 300.

His car is having a bizzare idle problem, when the car first starts up, it idles at 1600RPM (cold), then after a few minutes of just sitting there (it drops down to 800 and even dips to 500RPM!). The idle speed varies so much, its annoying and even at the really low idle, it causes the whole car to shudder and shake. I've noticed that his idle while driving and coming to a stop is less than 600... which is clearly not normal. I've also pulled two codes from the OBDII port, P0171 and P0125. One of the codes pertains to the car running lean, which could be MAF sensor related...

So my question is:

Can the MAF affect idle like this?

Also, on cleaning the MAF sensor, is there anything I should know about, aside from the obvious (because I don't normally repair japanese cars...).

BTW what is the normal idle speed? I couldn't find this on any label or marking under the hood...

Thanks!

PS. sorry for the last question, but I also noticed his upper passenger side engine mount is cracking? Does anyone know where I can purchase this part (besides the dealer)?

[SKperformance]

search IACV

[kelvin6]

Thanks!

I looked it up, and does anyone have any recommendations on how to get those four screws off?

I'm thinking of a offset screwdriver...

[R.Holmes]

Thanks!

I looked it up, and does anyone have any recommendations on how to get those four screws off?

I'm thinking of a offset screwdriver...

there is no need to remove the complete valve. Those four screws are a bear to remove!!!! Using an offset screwdriver won't do it. They are torqued so tight that an ordinary screwdriver only strips them. Just remove the two screws that hold the solenoid and remove the solenoid. Push in on the plunger,(moves just a little bit but can see it move) with your finger and spray carb. cleaner or a cleaner that drys fast, while plunger is depressed. Remove the vac hose going to the valve (Bottom) to see the carbon come out of the valve. That should do the trick. To tell you how tight those four screws are, I went to a wrecking yard and with the throttle assy. removed from the motor, I could not break those screw loose. even with penetrant oil. Screwdriver only stripped the screws. CAUTION Don't loose the o-ring on the solenoid when removing it.

[kelvin6]

So let me make sure I know what i'm about to attempt:

Push this plunger in? http://us.lexusownersclub.com/forums/index...ost&id=2853

Spray carb cleaner into the hole at the throttle body, and remove the vac line on the right (on the throttle body) of the picture?

If this is correct, then I will give it a go.

[mkeeney]

So let me make sure I know what i'm about to attempt:

Push this plunger in? http://us.lexusownersclub.com/forums/index...ost&id=2853

Spray carb cleaner into the hole at the throttle body, and remove the vac line on the right (on the throttle body) of the picture?

If this is correct, then I will give it a go.

That's not actually a plunger. The valve rotates, so instead of pushing that piece in, rotate it open and closed as you spray cleaner down into the slot in front of the throttle. I just did this job on our '97 this past weekend. I actually removed the throttle body and the IACV from the TB. It took about 2 hours from start to finish, but I was going very slowly and taking pictures as I went. I didn't have any difficulty removing the IACV screws after the TB was out. I think it's worth the extra time and trouble to remove the TB and IACV to completely clean the valve after seeing its condition. Mine does have 184,000 miles on it though, and it was completely black.