what to use to clean idle air control valve 90 ck1500

Username	Post: Idle air control valve (Topic#178045)
Silverado90 Contributor Posts: 101 Loc: Tarsus / Turkey Reg: 10-22-04 User Info Send Private Topic View Profile	12-27-07 08:54 AM - Post#1328027 hey all, yesterday i changed the IACV and now i have a very high idle.is there a way to adjust it or the truck should do it itself??? thank you 1961 Chevrolet Apache 10 -all stock but needs rebuilding, 1990 Chevrolet K1500-305 V8,700R4,LT255/75R16 BFGs All Terrains Email Report

Chevytech Subject Matter Expert - Senior Member Posts: 3967 Loc: Twin Cities, Minnesota, U... Reg: 04-25-04 User Info Send Private Topic View Profile	12-27-07 10:47 AM - Post#1328098 In response to Silverado90 If the IAC is working ok the computer should relearn the IAC position. Specific driving conditions must be met before the ECM/PCM will relearn the IAC position. Driving the vehicle may bring the IAC to the correct position. Is this on a 1990, or the 1997 you were asking about in the other post, or what? For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If your vehicle has been altered from stock, let us know about that too. Email Report
cdmhenry Very Senior Member Posts: 2408 Loc: Minden, NV. Reg: 09-14-00 User Info Send Private Topic View Profile	12-27-07 05:58 PM - Post#1328419 In response to Silverado90 Silverado90 Said: hey all, yesterday i changed the IACV and now i have a very high idle.is there a way to adjust it or the truck should do it itself??? thank you The instruction below was given to me and relates the procedure for big block TBI engines that have 2 injectors. Small blocks will be the same, but the recommended idle speed may be different. The "settings to check" are only numerical values the ECM (computer) has stored and are not something you can adjust with a tool. The values are only obtainable with a OBD1 scan tool. So... I offer it here for information only. The part of interest to you starts with the words "Sometimes the IAC gets confused". That is the basic IAC reset procedure. Unless you follow the procedures exactly as outlined below, you more than likely mess up the idle control circuit. The ECM will try to control the idle no matter what you do. The ECM controls the idle, NOT the throttle plate position. Be sure and pay attention to the detail about having the truck fully warm and IN GEAR when you set the idle. Setting the TBI idle speed: Two settings to double check on the TBI are: 1) the min. idle air setting, and 2) the base commanded idle speed and IAC counts. The min. air idle setting (a measure of the uncontrolled air bleed past the closed throttle blades) should cause a warm idle of 625 ± 25 RPM, when the IAC is fully closed and disconnected, the trans is in DRIVE, and the vehicle is held against the foot brake. Okay, how do you make sure it's fully closed? Is this its position at part throttle when warm? 1) Set park brake and block drive wheels. 2) Start engine and warm to about 190° F. 3) Stop engine. 4) With IAC valve connected, ground the Diagnostic Link Terminal at the ALDL connector under the dash. You ground terminal A to terminal B. 5) Turn the ignition to RUN, but do not start the engine. Wait at least 10 seconds, and the pintle will drive itself fully into the seat in the TB, effectively closing the IAC passageway. 6) With the ignition still in RUN, and with the terminals grounded as above, disconnect the connector from the IAC valve itself. Try to pull the connector "straight" off, and quickly. It is important to break all of the IAC valve circuits at once, otherwise the pintle may move. Alternately, you can also use a Service IAC controller tool to manually close the IAC valve. 7) Remove the ground you installed from the ALDL terminals. 8 ) These events will have eliminated the IAC from the system. 9) Start the engine, and allow it to idle in PARK or NEUTRAL until the idle stabilizes. 10) Shift it to DRIVE and hold it against the foot brake. 11) If the min. idle (625 ± 25 RPM) is not within specs (altitude also has an effect here) then you'll have to remove the cover plug that hides the linkage stop screw and ever so slightly adjust the blades either more open or closed to achieve the desired results. Drill a small pilot hole in the cover plug, and then use a small awl to pry/rotate it out. 12) When done, shut the engine off, and reconnect the IAC connector. 13) If needed, reset the IAC per the procedure outlined below. Sometimes the IAC gets confused about where it is. To reset it, follow this procedure: 1) With engine warm, disconnect the negative battery cable for 15-20 seconds. 2) Reconnect the negative battery cable. 3) Restart the engine for 5 seconds. 4) Key off for 10 seconds. 5) Restart engine. The IAC will have been forced to extend fully and then retract to a park position. The IAC should move to a new/proper start position based upon the start-up coolant temperature. You will have also cleared any learned IAC modifiers and the IAC system will begin to hunt down the proper idle as run time progresses. It's sometimes good to have an assistant control the key while you watch the IAC in motion, just to make sure it moves smoothly and properly. Every Government Interference In The Economy Consists Of Giving Unearned Benefit, Extorted By Force, To Some People At The Expense Of Others - Ayn Rand Email Report
Silverado90 Contributor Posts: 101 Loc: Tarsus / Turkey Reg: 10-22-04 User Info Send Private Topic View Profile	12-27-07 09:01 PM - Post#1328549 In response to cdmhenry truck is 1990. thanks guys. 1961 Chevrolet Apache 10 -all stock but needs rebuilding, 1990 Chevrolet K1500-305 V8,700R4,LT255/75R16 BFGs All Terrains Email Report
Silverado90 Contributor Posts: 101 Loc: Tarsus / Turkey Reg: 10-22-04 User Info Send Private Topic View Profile	12-28-07 05:48 AM - Post#1328651 In response to Silverado90 Sometimes the IAC gets confused about where it is. To reset it, follow this procedure: 1) With engine warm, disconnect the negative battery cable for 15-20 seconds. 2) Reconnect the negative battery cable. 3) Restart the engine for 5 seconds. 4) Key off for 10 seconds. 5) Restart engine. i tried these but didnt help out. it looks like IACV working backwards.when i try to start to engine in the mornings when the engine is Cold, engine dies lots of times(idle is very low). but when the engine gets warm idle increases very much .i let off the gas pedal and the truck is like going itself :))it should to be other way but i dont know what the problem is??? 1961 Chevrolet Apache 10 -all stock but needs rebuilding, 1990 Chevrolet K1500-305 V8,700R4,LT255/75R16 BFGs All Terrains Email Report
Chevytech Subject Matter Expert - Senior Member Posts: 3967 Loc: Twin Cities, Minnesota, U... Reg: 04-25-04 User Info Send Private Topic View Profile	12-28-07 07:38 AM - Post#1328709 In response to Silverado90 There may be another problem that is causing the IAC to not work correctly. Check to see if there are any trouble codes are in memory of the computer. Here are some web sites with the basics on retrieving codes without a scan tool or code reader. Poor drawing of ALDL but ok instruction + codes http://www.cfm-tech.com/gm_tbi_trouble_codes.htm OBDI terminal identification http://robertpowersmotors ports.freeservers.com/ima... OBDI illustration and instructions http://www.troublecodes.net/GM/ 1985 – 1990 trouble codes instructions http://www.iroczone.com/specs/TroubleCodes.htm For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If your vehicle has been altered from stock, let us know about that too. Email Report
Silverado90 Contributor Posts: 101 Loc: Tarsus / Turkey Reg: 10-22-04 User Info Send Private Topic View Profile	12-28-07 07:42 AM - Post#1328711 In response to Chevytech thank you chevytech.i ll check the links. 1961 Chevrolet Apache 10 -all stock but needs rebuilding, 1990 Chevrolet K1500-305 V8,700R4,LT255/75R16 BFGs All Terrains Email Report
cdmhenry Very Senior Member Posts: 2408 Loc: Minden, NV. Reg: 09-14-00 User Info Send Private Topic View Profile	12-29-07 05:52 PM - Post#1329948 In response to Silverado90 Silverado90 Said: Sometimes the IAC gets confused about where it is. To reset it, follow this procedure: 1) With engine warm, disconnect the negative battery cable for 15-20 seconds. 2) Reconnect the negative battery cable. 3) Restart the engine for 5 seconds. 4) Key off for 10 seconds. 5) Restart engine. i tried these but didnt help out. it looks like IACV working backwards.when i try to start to engine in the mornings when the engine is Cold, engine dies lots of times(idle is very low). but when the engine gets warm idle increases very much .i let off the gas pedal and the truck is like going itself :))it should to be other way but i dont know what the problem is??? Then you should try the procedure that starts with the words ""Okay, how do you make sure it's fully closed? Is this its position at part throttle when warm?"" The key thing is to be sure the IAC pintle will close AND seal. Inspect the pintle seat in the TBI body. Make sure the seat is clean & not scratched. If the IAC closes properly when warm and you still have a high idle, it's not the IAC itself that is the problem. Every Government Interference In The Economy Consists Of Giving Unearned Benefit, Extorted By Force, To Some People At The Expense Of Others - Ayn Rand Email Report
someotherguy Senior Moderator Posts: 29502 Loc: Texas Reg: 08-01-03 User Info Send Private Topic View Profile	12-30-07 04:26 AM - Post#1330157 In response to cdmhenry Also note that with the air cleaner off, you can look straight down into an open area of the top of the TBI unit and actually see the IAC pintle where it seats. You could have someone turn the key on while you watch to see what the pintle does. Richard 06 Silverado ISS / 06 Silverado SS / 06 300C SRT8 Email Report
Silverado90 Contributor Posts: 101 Loc: Tarsus / Turkey Reg: 10-22-04 User Info Send Private Topic View Profile	01-02-08 12:18 AM - Post#1332592 In response to someotherguy ok thanks Richard i ll try that. i have a another question abou the IACV.I am looking through the brands and all i can find is stantard motor products and Airtex.Can't find Acdelco.even in the acdelco.com there is only a connector numbered PT127.?? anybody know the acdelco part number?? thank you 1961 Chevrolet Apache 10 -all stock but needs rebuilding, 1990 Chevrolet K1500-305 V8,700R4,LT255/75R16 BFGs All Terrains Email Report
cdmhenry Very Senior Member Posts: 2408 Loc: Minden, NV. Reg: 09-14-00 User Info Send Private Topic View Profile	01-02-08 01:55 AM - Post#1332597 In response to Silverado90 Silverado90 Said: ok thanks Richard i ll try that. i have a another question abou the IACV.I am looking through the brands and all i can find is stantard motor products and Airtex.Can't find Acdelco.even in the acdelco.com there is only a connector numbered PT127.?? anybody know the acdelco part number?? thank you There is more than one IAC valve type. The difference is the connector. Oval body & square body. I don't have the P/N handy, but Delphi still makes them. Every Government Interference In The Economy Consists Of Giving Unearned Benefit, Extorted By Force, To Some People At The Expense Of Others - Ayn Rand Email Report