Just installed new carb in my 1989 honda. Used diagram to connect vacuum hoses back up, but car idle speed is too high - up to 2,000rpm. What could be wrong?

With due apologize, the very first thing which I would like to amend is that it is not 22 k but it is 2.2 k (2200 rpm).
To solve the problem please check the following:
- Vacuum leaks. (PCV valve, A/C idle up vacuum switch and actuator, vacuum hoses routing, gasket intake manifold, distributor vacuum dash pot.
- Valve clearance.
- Ignition system.
- Carburetor vents and lines for clogged.
- Idle speed solenoid switch and its connection. (Remove the solenoid, put a finger on its hole on the carburetor, start the engine keeping the finger on the hole. If it maintains the stable rpm replace the solenoid or check the voltage on the switch).
- Adjust the air fuel mixture.

Hi there:
I suggest check this links, according with the fuel system:
- Fig. 62: Vacuum hose routing-1989 carbureted Prelude (except California)
- Fig. 63: Vacuum hose routing-1989 carbureted Prelude (California)
- Fig. 64: Emission component schematic-1989 carbureted Prelude
- Fig. 65: Vacuum hose routing-1989 fuel injected Prelude


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check for vacuum leaks ---transmission actuator and hose
vent control hoses , any where the there is vacuum control
the idle air control sensor would be a suspect so check wiring , connections and the sensor itself

Could be a vacuum leak. Check all your vacuum hoses for old, cracked, brittle signs. Spray some carb cleaner around them. If idle changes, there it is. I had a high idle problem on my celica. was the intake manifold not sealed on the head.

I ran into the same thing on my mom's 89 accord.... I thought it was the choke..... but I found out it was a vacuum leak on a vacuum line.... I found it by spraying carb cleaner on hoses lines with car running it don't take a lot just spray a little and if the engine revs up more you know where about the leak is and can inspect it.... check the intake around the carb and vac lines too...

check for vacuum leaks on hoses and connections as well as check intake gasket for leak by spraying carb cleaner around the gasket mating area,if rpm changes then that is where the leak is.

If you have a carb, and nothing but a carb, you probably need to have your carb adjusted. If your carb has an automatic choke, it could be stuck. Check and make sure the choke's butterfly valve (the one in the top of the carb) is opening up once your engine has warmed up. If it doesn't, disconnect the valve from the auto choke and manually open it, that should change idle. Do not drive with the choke disconnected. Write me back if that doesnt solve the problem.

Sounds like a possibility of a vacuum leak. Inspect the vacuum tubing for damage or wear or just not being connected. One mechanic's trick is to spray carburetor cleaner on the vacuum lines with the engine running. Use safety goggles when trying this. If there is a vacuum leak - when the carb cleaner hits it the engine will speed up.

1986-1989 Honda Accord with Carburetor have a very bad habit that is little known even by most mechanics but easily fixed at home. The vacuum port on the choke opener that is connected to the intake manifold and both vacuum ports on the fast idle unloader get plugged up with nasty hard carbon almost as hard as metal. When this happens the choke sticks closed and the idle sticks on fast idle when the engine is cold and nobody can figure out why. All you have to do is attach a small drill bit to the end of a flexible socket-driver extension and put it in a variable speed drill that will let you run it real slow and carefully drill out the vacuum ports that are plugged. After they are nice and clean use a vacuum pump tester to make sure the choke opener and fast idle unloader are working before putting it all back together. It's amazing how much better the car runs after cleaning out those ports.

These are a vacuum line nightmare. I take it the diagram isn't still on the bottom of the hood?