IAC Valve?!?
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Freshman User
Joined: Aug 2004
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IAC Valve?!?
I was reading a bunch of posts on the IAC Valve. Well I think mine might be going or is shot. I drive a 94 Ranger 4.0 V6. I recently put a cold air intake on it and now sometimes, not always but most of the time when i start it up my idle goes real high to about 2,000-2,500 rpms then i shut it off, and start it back up and sometimes it idles normal about 500-600. So i put the stock intake back on, i took the IAC valve off and cleaned it out with some carb. cleaner, i reset the computer by take the battery cables off and cleaned the throttle body out at my last oil change about 800 miles ago. So basically i start it up sometimes its fine but when its not it idles real high, and if it drops it almost stalls my engine out. So my best guess is to replace the valve and pray thats it. It happened once while i was drivng too and it was kinda scary cause i had to slam on the brakes and i hear my engine reving up when im braking im like ahhh. What are the symptoms for the EGR Valve sticking open? Cause for some reason that doesn't fix the problem could it be the EGR valve stuck open. Thanks i need all the help i can get.
Post Fiend
Joined: Jan 2003
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From: Connecticut
Junior User
Joined: Dec 2004
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I agree with Rockledge to pull the codes. Although, there may not be any codes registered.
I've been having a similar problem with my '95 Ranger 2.3L 4-banger for the past year that was a pain to diagnose -- no codes ever showed up. (Search for my previous posts to see if our situations are similar).
I ended up cleaning the IAC really well and spraying some throttle body cleaner into the intake manifold itself where the IAC connects to it. It starts right up and idles really well now. I bought a new IAC valve at Advance Auto Parts for $40. I'm going to spray more throttle body cleaner into the IM this weekend and really clean it out, then install the new IAC.
Good Luck!
I've been having a similar problem with my '95 Ranger 2.3L 4-banger for the past year that was a pain to diagnose -- no codes ever showed up. (Search for my previous posts to see if our situations are similar).
I ended up cleaning the IAC really well and spraying some throttle body cleaner into the intake manifold itself where the IAC connects to it. It starts right up and idles really well now. I bought a new IAC valve at Advance Auto Parts for $40. I'm going to spray more throttle body cleaner into the IM this weekend and really clean it out, then install the new IAC.
Good Luck!
Post Fiend
Joined: Feb 2003
Posts: 6,940
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From: Eastern WA
94 Ranger 4.0's do not have an EGR unless they were originally sold in californianland. As for throwing parts at something on a hunch, you could do this but often it proves to be expensive guessing. I'd say first pull codes. If there are no codes, I'd run the pinpoint tests on the IAC system.
Cargo Master
Joined: Feb 2002
Posts: 2,414
Likes: 22
From: Tucson USA
I have the same problem on my 94 4.0. I finally just disconnected the stupid thing as we traced the potential problem to a wire in the wire bundle. spent a couple ofhours searching and looking at the codes that would show up and then breaking them down 1 by 1.
Anyhow I pulled the connector off, ran the throttle screw up a little and it idles at 6=750rpm with and without ac on. It will drop low when I first start up so I need to give it a little throttle initially. Other than that no problems, passes emmisions etc.
might want to consider trying it.
Anyhow I pulled the connector off, ran the throttle screw up a little and it idles at 6=750rpm with and without ac on. It will drop low when I first start up so I need to give it a little throttle initially. Other than that no problems, passes emmisions etc.
might want to consider trying it.
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Freshman User
Joined: Aug 2004
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well i ran the test no codes came up, my teacher and I were looking all over checking all vaccuum lines, everything. When i replaced the upper intake manifold gasket i had my partner tighten the bold for the throttle linkage well he said it was tight but i found out it was held on by about 1 thread. I tightended it up and haven't had a problem since. The IAC Valve was working good i took it off and tapped it in my hand and you could hear it moving.
