Should I Remove & Clean the IAC Seperately

8113 Views 24 Replies 13 Participants Last post by grandpapa, Sep 8, 2010

snarley55

Discussion Starter · Aug 12, 2010

Greetings All,
'96 Camry 140,000 miles, 4 cylinder, automatic
Starts, stalls immediately. Per FAQ, removed intake boot, propped butterfly open, cleaned with carb cleaner and toothbrush. Reassembled. After warming up, car will idle, but very low, around 350 rpm.
Should I remove the throttle body and IAC and disassemble and clean the IAC seperately or is there another direction I should be looking? Thanks

1 - 20 of 25 Posts

TOYOPARTSMAN

· #2 · Aug 12, 2010

don't know how thorogh of a job you can do cleaning the IAC valve. You may want to consider replacing it.

When you say low RPM's I do know that intak hose that goes to the throttle body sometimes develops cracks and can leak, almost like a straw with a hole it in. Have you checked it or replaced it recently?

snarley55 said:
Greetings All,
'96 Camry 140,000 miles, 4 cylinder, automatic
Starts, stalls immediately. Per FAQ, removed intake boot, propped butterfly open, cleaned with carb cleaner and toothbrush. Reassembled. After warming up, car will idle, but very low, around 350 rpm.
Should I remove the throttle body and IAC and disassemble and clean the IAC seperately or is there another direction I should be looking? Thanks

snarley55

Discussion Starter · #3 · Aug 12, 2010

Thanks. Now that it will idle, I'll listen and feel for any air leaks.

TOYOPARTSMAN

· #4 · Aug 12, 2010

No problem. If you should happen to need either an IAC or that hose, any information, or just have a question, don't hesitate to contact me. I offer TN members 30% off Genuine OEM Toyota parts. Feel free to contact me. We do not over inflate shipping in order to make up any differences in the discount. WE only charge actual shipping costs plus a couple of dollars for materials etc. We do mean a couple $2.00 dollars.

We want to provide the TN members with a place to get OEM parts at a reasonable price.

We are also here to help the TN members with more than just a parts sale, if you have any questions or want to run something buy me, don't hesitate.

snarley55 said:
Thanks. Now that it will idle, I'll listen and feel for any air leaks.

Mike Gerber

· #5 · Aug 12, 2010

It's not usually necessary to remove the idle air control valve to clean it. It does become necessary on some occasions, if it is very dirty. Did you spray the cleaner liberally down in to the square or diamond shaped port in the base of the throttle body? That port leads to the idle air control valve. If not, do the cleaning again. Here's thread on how to clean it on the 5SFE engine and it has some great pictures including the port leading to the idle iar control valve:

http://www.toyotanation.com/forum/showthread.php?t=158097

Mike

mr2crazed

· #6 · Aug 31, 2010

Kinda having the same problem with my '94 with an I4 with about 183k on it. I've cleaned the throttle body and IAC port multiple times now and still won't start cold unless you give it some gas.

Wondering if it's worth it to remove the IAC for a more thorough cleaning. Or am I better off replacing the IAC?

BamZipPow

· #7 · Aug 31, 2010

mr2crazed said:
Kinda having the same problem with my '94 with an I4 with about 183k on it. I've cleaned the throttle body and IAC port multiple times now and still won't start cold unless you give it some gas.

Wondering if it's worth it to remove the IAC for a more thorough cleaning. Or am I better off replacing the IAC?

Something else to consider is yer TPS and cold start injector (not sure if yer engine has cold start injector or not).

TCam01

· #8 · Aug 31, 2010

you need to take the iac off separately and lube that shutter valve that's where my problems came from

uibalnme

· #9 · Aug 31, 2010

These engines (V6 or I4) don't have cold start injectors. The ECU just runs the A/F mix rich until the engine warms up.

It's just not worth the cost replacing the IAC valve. Remove the throttle body, take off the IAC valve, and give it a good cleaning with some brake cleaner(or any other strong solvent) and a small brush/Q-tips. Then reinstall, and pat yourself on the back for saving a big wad of cash.

I cleaned my IAC valve a while back. It was pretty well gummed up. After the cleaning, it starts, and idles perfectly in the morning.

ajkalian

· #10 · Aug 31, 2010

uibalnme said:
It's just not worth the cost replacing the IAC valve. Remove the throttle body, take off the IAC valve, and give it a good cleaning with some brake cleaner(or any other strong solvent) and a small brush/Q-tips. Then reinstall, and pat yourself on the back for saving a big wad of cash.

I cleaned my IAC valve a while back. It was pretty well gummed up. After the cleaning, it starts, and idles perfectly in the morning.

+1 to this suggestion. There is no way spraying anything down the hole in the throttle body will clean the IACV properly. Once you take one apart you will see what I mean. Mine was full of black carbon deposits that took some real scrubbing to get loose. The rotary sleeve wouldn't rotate. Once completely disassembled all parts could be cleaned shiny new, and working smoothly. Once put back on the car the difference was very noticeable. Like uibalnme said, it idles perfectly.

One note of caution if you attempt this, depending on your year/configuration. Be sure to mark the hoses going to the IACV, so you don't mix them up. One is for engine vacuum, the other two are for engine coolant. Mix them up, and expect much grief.

Another thing to watch out for, is the screws that hold the IACV to the Throttle Body. They are the crappiest, softest metal I have ever seen. The Phillips screws strip out if you just look at them. Get a large Phillips screwdriver, press really hard, twist sharply, and hope the screw comes loose. If not you will have to grind a slot in the Phillips head, and use a flat blade screwdriver. In any event, throw the stock screws away, and replace them with hex head bolts. Then no problem tightening them up, or loosening them up for future cleaning.

Once you've done it, it's not that hard of a repair, and your motor will love you for cleaning it's IACV.

.

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peshwa

· #11 · Aug 31, 2010

Thanks ajkalian for the nice tips! Does the throttle body gasket need replacement too? Is it reusable?
I plan to tackle this over the long weekend and give my baby some love...

ajkalian

· #12 · Aug 31, 2010

peshwa said:
Thanks ajkalian for the nice tips! Does the throttle body gasket need replacement too? Is it reusable?

The gasket is embossed, thin metal, and it gets flattened when you tighten the bolts. You could re-use it with some RTV, but it should be replaced with a new one.

Be sure to mark the Throttle Body gasket before you take it off. It fits more than one way, and if you get it on wrong, your engine will run like crap. Ask me how I know. If you get a new gasket, supposedly RTV isn't necessary, although I slop gasket sealer on everything just for good measure.

Check the Air Cleaner Cover at the very bottom edge towards the firewall. Depending on your model, it might have a rubber EVAP hose connected to the Air Cleaner Cover. It's easy for it to pull off when you remove the Air Cleaner Cover and not get it re-connected.

Let us know how it goes. Maybe even take a few pics, maybe do a write-up?

.

grandpapa

· #13 · Aug 31, 2010

peshwa said:
Thanks ajkalian for the nice tips! Does the throttle body gasket need replacement too? Is it reusable?
I plan to tackle this over the long weekend and give my baby some love...

remember to take pictures. For people like me, I need picutre so I can follow what's going on. thanks

grandpapa

· #14 · Aug 31, 2010

Do you have to drain the coolant 1st? I think there is one hose connected under the IAC valve. Just wonder if you can just disconnect the hose without draining the coolant.

ajkalian

· #15 · Aug 31, 2010

grandpapa said:
Do you have to drain the coolant 1st? I think there is one hose connected under the IAC valve. Just wonder if you can just disconnect the hose without draining the coolant.

If you have a clean container, the drain the coolant into it. You don't have to drain all of it.

If unsure, then disconnect the coolant lines from the IACV and just enough coolant will drain out....all over the floor. :facepalm: jk

mr2crazed

· #16 · Sep 1, 2010

ajkalian said:
+1 to this suggestion. There is no way spraying anything down the hole in the throttle body will clean the IACV properly. Once you take one apart you will see what I mean. Mine was full of black carbon deposits that took some real scrubbing to get loose. The rotary sleeve wouldn't rotate. Once completely disassembled all parts could be cleaned shiny new, and working smoothly. Once put back on the car the difference was very noticeable. Like uibalnme said, it idles perfectly.

ajkalian,

Did use any lubricant on the rotary sleeve once everything was cleaned up inside the IAC?

I'm picking up new gaskets today from Toyota, nobody else carried the IAC gasket. I plan on tackling this job this weekend and if I remember, I'll take some pictures of the process and repost.

LittleWhiteBubble

· #17 · Sep 1, 2010

Don't put any grease or anything on it that will cause buildup to stick to it. I cleaned mine a while back and I didn't lubricate anything after cleaning, it caused me no problems.

ajkalian

· #18 · Sep 1, 2010

mr2crazed said:
ajkalian,

Did use any lubricant on the rotary sleeve once everything was cleaned up inside the IAC?

I don't think I used any oil, but I can't remember for sure. When you get it off the throttle body, there is a plastic block thing on one side. That is the electromagnetic motor.

Kinda like a Sonicare toothbrush

Or at least that's what I think it is. There is no physical contact between the "motor" and the sleeve/valve that it rotates. I took everything apart. I noticed that the gasket material that held on the plastic block was kinda weird. Since I didn't have any of that weird type of gasket sealer, I just used the normal RTV, but use it sparingly. You probably could get by using nothing, and IIRC there isn't a gasket on the motor to the body, but I could be wrong.

This will all make sense when you get it apart on the bench. Keep in mind that the rotary valve/sleeve rotates 360 degrees. Mine was so munged up so bad it only rotated a little, but after I took it out, and cleaned it, it spun freely in the body.

One thing you will come away with after you finish, is that this whole system is way too complicated. Especially if you have a Calif spec model with coolant hoses. Way too much stuff in such a small area.

OK, I'm done now.....:lol:

.

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AliRazoR

· #19 · Sep 1, 2010

LittleWhiteBubble said:
Don't put any grease or anything on it that will cause buildup to stick to it. I cleaned mine a while back and I didn't lubricate anything after cleaning, it caused me no problems.

i have 1 question,did you drain your coolant?
i am going to clean IAC and throttle because of that i ask you.
is it enough to drain radiator only?(or we have to drain engine as well?)

uibalnme

· #20 · Sep 1, 2010

you don't have to drain the coolant. some will be lost when you disconnect the hoses, but nothing major.

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