Engine high idle?

Clean the throttle plate with choke cleaner on both sides first as well as the iac hole. Which O2 sensor has no activity you may have replaced the wrong one and is it due to a bad connection?

Normally a high idle is caused by a vacuum leak. One concern is that the ECM should be setting an idle speed error.

I would check for vacuum leaks, and remove/clean the IAC and base.

You could remove and clean the IAC, but an idle that high (4-5K) is most likely a vacuum leak and a big one like a power brake booster line.

I would probably take a look at the car yourself, I really doubt it is 4-5K, and is most likely an IAC, since vacuum leaks don't fix themselves :).

Is Data Link Connector 12 or 16 pin? Suspect IAC causing problem remove and clean maybe carbon holding pentil open

Most of this particular year are OBD1 system with OBD2 connector and will not give flash code nor will they read with a generic code reader. They require a professional scan tool to access codes on this one year.

You may have a bad IAC ( idle air control) but try eliminating any vacuum leaks and cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.

Let's hope so.

Could be the idle air control valve try cleaning out and see what happens

Too fast an idle speed. If an engine without computerized idle speed control is idling too fast and refuses to come down to a normal idle speed despite your best efforts to back off the carburetor idle speed screw or air bypass adjustment screw (fuel injection), air is getting past the throttle somewhere. Common leak paths include the carburetor and throttle body gaskets, carburetor insulator spacers, intake manifold gaskets, and of course, any of the engine's vacuum fittings, hoses and accessories. It is even possible that leaky O-rings around the fuel injectors are allowing air to leak past the seals. Another overlooked item can be a worn throttle shaft and a defective idle speed speed control motor/valve stuck in the extended (high idle speed) position/throttle position sensor. Also the throttle plate could be binding in its bore and kinked accelerator cable, coolant temperature sensor might not be operating properly misleading the computer that the engine is still cold and computer throwing fuel at it raising the idle speed.

Have you called shop and told them whats going on? May have left engine temperature sensor unplugged on rear of engine see if it is unplugged. May need to remove air cleaner to gain access.

Hey CINDY,

Yes that is near the TPS sensor maybe they bumped the connector and now it has a bad connection. Is the check engine light on?

Also they could have left off or not properly connected the air intake boot,, here are a couple of guides that will help you.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/replace-an-air-intake-boot

Run some tests and get back to us so we can continue helping you.

Best, Ken

Typical of a vacuum leak. Check the vacuum hoses for leaks and the intake manifold gaskets. When the engine is still cold and running, use a spray bottle to spray water on the gaskets. If you see it get sucked in and the engine slows down momentarily, you've found the leak.

You most likely have a vacuum leak somewhere, vacuum line, brake booster, intake manifold gasket, fuel injector O-ring.

If you put the car in diagnostic mode (jump terminals A and B of the ALDL), this should move the IAC to the fully closed position (you should hear it buzzing).

If not then the IAC may be bad.

But the IAC is designed to control the idle within a range of about 700 rpm, so I still think you have a vacuum leak somewhere.