1991 Camry idles really fast

[irhy]

Hi everyone,

I have a 1991 Camry with a 2 liter, 3sfe engine with a quarter of a million miles on it. The last 5 weekends I've driven from Chicago to St. Louis and back. After the first couple of times, I've noticed that the engine idles very fast. It sounds like I'm gunning the engine. With the car in drive and my foot off the gas, it goes up to 40 mph. I wasn't having any problems before. What could be causing this?

[Mike Gerber]

Check first for disconnected vacuum lines. It sounds like you may have a large vacuum leak somewhere. Also check the large tube that connects to the throttle body for cracks. If that isn't the problem, clean the throttle body. Do a search on this forum for "throttle body cleaning" for instructions. If the problem still exhists after that, check the accelerator cables for binding.

Mike

[Brian R.]

Could also be your ECT sensor. If your ECM thinks your engine is cold, it may be giving you a fast idle/rich mixture.

[irhy]

Thanks for the replies. I did a search before I posted and noticed some messages about Seafoam. I'll give it a try.

[Brian R.]

Check the ECT sensor also.

[Toysrme]

Throttle plate is stuck open.


Clean it & while you're in there, the IAC, and EGR valves.

[irhy]

Originally Posted by Brian R.

Check the ECT sensor also.

I'll check that too.

Originally Posted by Toysrme

Throttle plate is stuck open.

Clean it & while you're in there, the IAC, and EGR valves.

Won't Seafoam clean all of that?

[Toysrme]

No. It can clean it, but not without doing it by hand & scrubbing.

[irhy]

A new problem has arisen today. After starting the car and driving it for a couple of minutes, the check engine light comes on. I shorted the E1 and TE1 terminals to get the error codes. The ones I get are: 25, 26, and 43.

I'm going to clean the throttle plate tomorrow. I was going to use Sea Foam "Deep Creep" to clean it.

[gspservice]

Originally Posted by irhy

A new problem has arisen today. After starting the car and driving it for a couple of minutes, the check engine light comes on. I shorted the E1 and TE1 terminals to get the error codes. The ones I get are: 25, 26, and 43.

I'm going to clean the throttle plate tomorrow. I was going to use Sea Foam "Deep Creep" to clean it.

well the first 2 are air to fuel ratio often the fault of the oxygen sensor. But there are a rew other things that can cause it

[irhy]

It turns out that the connector to the O2 sensor had cracked off. I replaced it and the check engine light light went away.

I cleaned the throttle body and butterfly valve with a can of SeaFoam Deep Creep, sucked a 1/4 of a bottle of SeaFoam thru the brake booster hose 4 times, added 1/2 of a bottle to the oil when I changed it and put the other 1/2 of a bottle in the gas tank when I filled up. The car idles *MUCH* smoother. And they're not kidding when they say it will make a lot of smoke!

It still idles really fast. I'm going to check the ECT sensor, but when I looked for it at www.autozone.com, it says there isn't one. It has a coolant temperature sensor though. Is that the same thing as the ECT sensor?


*EDIT*

I just searched Napa's website for "sensor" and there's a "Coolant Temp Sensor", a "Engine Temp Sensor", and a "Throttle Position Sensor". Which is the equivalent to the ECT sensor? There are some other sensors but I don't think it's any of them.

[Brian R.]

Coolant temp sensor is correct. They may have it listed under Engine temp sensor also, but I don't know for sure. If you're curious, you can always compare the part numbers for your vehicle.

[irhy]

I changed the coolant temp sensor and it seems like it might have helped a little, but it still idles high. I tried checking the resistance of the ISC valve but it was really hard to get the multimeter leads in there. I think it's bad and the reading I got was 0 ohms. I might have done it wrong though. Can I take the throttle body off and check it? If it is bad, can cleaning it fix it?