p0505 high idle

Posted by Rustic gst, May 19, 2017
Newbie Forum - Beginner DSM modification questions and discussions. Common, repetitive, and general discussions will get dumped here from other tech forums. Unless you're a Probationary member you shouldn't post threads here.

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  1. Rustic gst

    Rustic gst Probationary Member

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    las vegas, New_Mexico
    hey guys so i recently had a idle surge between like 300rpm and 900 and i could idle right. it never died on me once started but i do have a cold start problem. i replaced my idle air control valve and it didn't seem to change. so i took my throttle body out, cleaned it and closed off the fiav. now my cars idle is really high between 1200rpms to 1800 rpms. is there any way to test the connector to the iac valve to make sure that my wiring to the sensor is not bad? also i can plug and unplug the connector on the iac and i see no noticeable change in idle
     
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  2. Vegas smith

    Vegas smith Proven Member

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  3. Rustic gst

    Rustic gst Probationary Member

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    the cable doesnt seem to have moved plus i was having a idle problem before removing the throttle body. it runs fine under boost no hesitation or misfire at wot
     
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  4. Brando420a

    Brando420a Probationary Member

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    i had the same problem exactly. i replaced the IAC and i replaced the TPS and cleaned it just like you did and still had that high idol
    i met a guy who was a DSM expert and he told me to replace the throttle body so i did and it fixed the problem. so if i were you id do that. i think what i cleand it with might hav caused the problem i used WD40 to clean it with but idk if you look at my dsm profile you can see all the posts i said about my idol issue and how long it took to figure it out, and trust me it had me stumped i still dont know exactly why or what made the two difference but try it out it wont hurt
     
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  5. Rustic gst

    Rustic gst Probationary Member

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    yeah i was thinking about replacing the throttle body next only thing is i cant find one for a reasonable price
     
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  6. Brando420a

    Brando420a Probationary Member

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    Honestly I got mine from the junkyard and just cleaned it up not with WD but with brake cleaner and it works just fine was fairly cheap
     
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  7. Rustic gst

    Rustic gst Probationary Member

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    is there any way to test the connector to the idle speed sensor? like with a voltmeter?
     
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  8. Vegas smith

    Vegas smith Proven Member

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    You need to test the iac with a voltimeter. Do a quick search on how do that. If that doesn't work then check your ecu for driver damage.
     
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  9. Vegas smith

    Vegas smith Proven Member

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    You really don't need a new tb either. Just buy some new tb seals and a biss screw o-ring and you can rebuild it all yourself which is what I did recently. Idle issues are extremely common on these cars so you have to be very diligent and research all the ways you can have a bad idle.
     
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  10. Brando420a

    Brando420a Probationary Member

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    you could test the voltage on your IAC and actually you can take it out of the back of the throttle body and turn the key to the on position and see it move in and out if dosnt move it's bad if it moves and shoots like a rocket and brakes apart like mine did before it's obviously bad. As for the throttle positioning sensor TPS you can test that to see if you get the right voltage. Disconnect the connector set you volt meter to ohm's between 2 and 3 and you should get between 3.5 and 6.5 k-ohms. Open the throttle slowly and watch the meter change smoothly if it stays within those specifications then it is good if not it is no good
     
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  11. Rustic gst

    Rustic gst Probationary Member

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    ok so i got a brand used throttle body from a parts car, tuns out one of the coils on the iac were fried. so i ordered a new one from auto zone slapped it on and there is no difference in my idle. the check engine light has gone off though. i also noticed when im cruising in low rpms lets say 40 mph in 5th gear and im at light throttle like 15% my car bucks whenever i move the pedal up or down to regulate speed. however it doesn't do this when my rpms are higher. i cleaned my egr and it made no difference. i ordered a egr block off plate and im gonna try to delete the egr, hopefully it is faulty because i dont know what else to do
     
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