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1999 Amigo v-6 55,000 miles, starts and runs fine. It just started idling between 1500 - 2000 rpm one day and now does it constantly. I removed the EGR and PCV and cleaned with carb cleaner, I replaced the spark plugs, i have unhooked and hooked back up all sensor connections that I can find, I have checked all vacuum lines(that I can get to). I have sprayed WD-40 around the entire intake to check for leaks and still nothing. The only time I get a check engine light is when I unhook sensors. As soon as I hook them back up and unhook the battery, it clears and stays off. I have purchased two O2 sensors but haven't replaced them yet. Just looking for some more info on this. Is there a specific sensor I should replace or a certain area to look for vacuum leaks? Thanks Doug
 

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Doug- don't spray WD40 around the intake manifold/ air intake!!! I'm not sure if this stuff contains silicone, but if it does, you will destroy your oxygen sensors. Only use a quality, sensor safe carburetor cleaner for IMG leak checking. The only other thing I can think of that could cause high idle, is there is a small wire connector going to the power streering pump. There is a sensor built into the PS pump that activates an engine high idle mode to compensate for the load the PS pump puts on the engine during idle/low speeds. Make sure the wire(s) & connector are making a good connection. IIRC- if you disconnect this, your rig will idle rediculously high. G/luck
Joel
 

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thanks Joel, I looked for the wire you are talking about but could not find it. I will look again and make sure it is connected properly. If it is already connected properly, could the sensor that is in the pump be bad? sending it the message to idle high? Is it a replacable sensor? Also, do you think it is worth while replacing the O2 sensors? If one or both were bad, wouldn't they set off the check eng. light? thanks again! Doug
 

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Howdy. Distance repair is difficult, but it sure sounds like a vacuum leak especially since there are no codes.

Another way to check to see if you have a short or open on the pwr steering idle up circuit is to hook up a tach on the engine, be in a neutral position (sometimes you have to be in a geared position), and turn the steering wheel all the way to one side or another. Generally speaking, the PS idle up circuit only works at the extreme ends of the steering rack, or "lock to lock". You should see at least a 50 rpm difference between your steering wheel being in the center vs. at the lock. How's the level on your fluid?

On the intake manifold gasket, Joel is on the money. You don't want to use WD-40 or brake cleaner. There are 2 same things to use, one is carb cleaner, the other is simply water. Yes, water. I personally like water because I'm a little sensative to carb cleaner. Also, water is free and doesn't evaporate as quickly, which can be helpful at times. If you do use water just make sure not to dump it on, i.e. use a spray bottle. If you dump it on there and let it build up (particularly with cold H2O) you can crack the manifold. The same thing can happen if you do water-crossings when 4 wheelin'.

ASIDE: I know there have been many posts on seafoam, and it certainly has it's merits. However, water can be shot directly into your intake manifold and "steam clean" the cylinders. Just raise your RPMs and use a spray bottle to mist the water in the intake. Don't add too much or your hydro lock your motor. Anyway, you'll see some carbon spit out your tailpipe as a result of the steam cleaning. An old farmers trick.

-Kevin
 

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common concern disconnect powersteering pressure switch you dont really need it it is designed to increase engine speed when there is an increased load on the engine your V-6 is going to be just fine without it unplug it and forget it

Isuzu's fix remove power steering pressure switch clean it reinstall it flush p/s sys. (does not always work) and it is hell to get it back in place without breaking the wire off of the sensor

debris in the switch is causing it to hang up and idle the vehile to about 3,000 RPM's
 
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