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Discussion Starter #1
I have a 89 gts. For some reason now that when I start the car it revs up to 2k rpms. As I drive and it warms up it used to go down but now it stays at 1700 when stopped and clutch is pushed in, but now when it warms up as I am rolling with the clutch pushed in it will rev to 1300 then drop to 900 then rev to 1300 drop to 900, and over and over again till I stop then it just revs to 1700 again. Any Idea?
 

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1988 Corolla SR-5
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Check the idle air control valve attached to the throttle body.
It is supposed to open when the engine (coolant) is cold, and close off as it warms up.
If it gets filled with grease and grime it will hang up.

Follow the two coolant hoses that go to the throttle body and there it is.

There are two air hoses that go to it also, those could be a problem too. One should go to a valve on the steering rack, and the little tit on that valve can break off and give you a vacuum leak.
 
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Discussion Starter #5
Check the idle air control valve attached to the throttle body.
It is supposed to open when the engine (coolant) is cold, and close off as it warms up.
If it gets filled with grease and grime it will hang up.

Follow the two coolant hoses that go to the throttle body and there it is.

There are two air hoses that go to it also, those could be a problem too. One should go to a valve on the steering rack, and the little tit on that valve can break off and give you a vacuum leak.
Thanks donald going to check tomorrow morning
 

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Discussion Starter #6
Now it is idling around 2500 when cold then when it warms a bit it revs up then drops then revs up then drops. I am about to drive it off a cliff. I checked and can not find a vacuum leak. I am at a loss
 

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MagAuto.com Parts Master
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Hi, this is Joe from www.MagAuto.com, OEM Toyota parts at wholesale prices. I read the thread on this post entirely; it sounds like an IAC motor, like Donald said. If not, give your throttle body a look over, maybe a good cleaning.

Joe
 

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MagAuto.com Parts Master
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Give it a good cleaning. A quality induction system cleaner will include an aerosol can that (after removing the intake tube from the throttle body) you should spray onto the throttle body butterfly. If that solves your problem, sweet, it was a cheap fix. If it comes back within the next few days, I would assume it's your IAC motor.

How is your throttle response when driving? Do your revs fluctuate all over the place when you're cruising (staying within what SHOULD be a relatively constant rpm range)? If so, sounds like it might be a throttle body. Does it run rough in addition to your RPMs jumping when it's in park/neutral? That might indicate injectors being clogged. If that's the case, that induction cleaner I mentioned can help. Get yourself a kit that includes the aerosol throttle body cleaner AND a fuel additive to clean your injectors.

Hope this helps. Visit www.MagAuto.com to get good deals on any parts you need for your repair.
 

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Discussion Starter #10 (Edited)
Give it a good cleaning. A quality induction system cleaner will include an aerosol can that (after removing the intake tube from the throttle body) you should spray onto the throttle body butterfly. If that solves your problem, sweet, it was a cheap fix. If it comes back within the next few days, I would assume it's your IAC motor.

How is your throttle response when driving? Do your revs fluctuate all over the place when you're cruising (staying within what SHOULD be a relatively constant rpm range)? If so, sounds like it might be a throttle body. Does it run rough in addition to your RPMs jumping when it's in park/neutral? That might indicate injectors being clogged. If that's the case, that induction cleaner I mentioned can help. Get yourself a kit that includes the aerosol throttle body cleaner AND a fuel additive to clean your injectors.

Hope this helps. Visit www.MagAuto.com to get good deals on any parts you need for your repair.
no, it has good throttle response, and not very rough at all so I am not to sure
 

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Before you replace it try cleaning it. Take the rubber air intake off throttle body and look for the large square hole on inside bottom of throttle body. This is the port you want to give a large spray of throttle body cleaner.. Can try spraying and letting it sit to soak in. When you go to restart will probably have to hold gas pedal slightly to clear it out. Also if your car is running cold (due to a bad thermostat) it will cause the valve to not operate correctly as it has a passage where coolant passes through it to deactivate it when engine is warmed up. This is assuming you have the 4AFE.
 

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The Return of the Red Coupe
2010 RAV4 V6
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have you changed the thermostat? if it's stuck open, the temp sensor will think the car is not warm enough and keep cycling warm up mode.
 

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1988 Corolla SR-5
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I think I should have 2. One off my '89 GTS and one off the '87 FX-16 that I am doing an engine swap on.
I'll have to check tomorrow to see if they look any good. I'll let you know what I find.
 

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Discussion Starter #15
I think I should have 2. One off my '89 GTS and one off the '87 FX-16 that I am doing an engine swap on.
I'll have to check tomorrow to see if they look any good. I'll let you know what I find.
yes please do, And it is for a 4age
 

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1988 Corolla SR-5
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I pulled them both, and both look ok, but you really can't tell if they are good by just looking at them.
They are not all gummed up nor are the water passages choked up.

The one off my GT-S should be good because it was working fine before the crank shaft broke, so if you want that one, make me an offer.

e-mail: [email protected]
 
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