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  Topic Review (Newest First)
July 16th, 2013 10:09 PM
krupa35 Very informative, thank you cliff! I'll try and clean to see what happens first, if its still failing I will replace with Motorcraft
July 16th, 2013 08:59 PM
cliffyk
Quote:
Originally Posted by krupa35 View Post
Late bump, but mine is making a very loud buzzing noise. How do you clean them? I have an "02 GT with a K&N so im not sure if its different from OEM...?
The buzzing/honking noise is a result of the IAC being worn and the valve plunger vibrating inside its bore (see below). This is not uncommon, cleaning it generally makes it worse as it removes crap that may be hindering the vibrations. Replacing it is a more viable solution.

When mine began honking I cut the old one apart to see why:

July 16th, 2013 04:42 PM
krupa35 Late bump, but mine is making a very loud buzzing noise. How do you clean them? I have an "02 GT with a K&N so im not sure if its different from OEM...?
May 20th, 2013 03:18 PM
arummel93 Yeah, I try to avoid screwing around with wiring, but sometimes it's necessary. So when I do, I just break out the sewing supplies and get to it. I'd likely get something like cliffyk was talking about if I had to do it a lot.
May 20th, 2013 03:03 PM
cliffyk Pins are cool if it's not something you need to do all the time--watch for shorts!
May 20th, 2013 12:56 PM
dark_horse
Quote:
Originally Posted by arummel93 View Post
Straight pins (think clothing store pins) have always worked fine for me!
Not a bad idea man, I'm gonna try that lol

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May 19th, 2013 11:49 PM
arummel93 Straight pins (think clothing store pins) have always worked fine for me!
May 19th, 2013 08:56 PM
cliffyk The best way is with to with the key on and engine off (KOEO) back probe or use insulation piercing probes to monitor the TPS output signal--between the gray/white wire and ground--and compare it to the graphs I posted above. This one test confirms or denies both the consistency of the Vref (+5 V reference) signal from the PCM, and the TPS's operation.

The output voltage, as you open and close the throttle, should follow the line in the graph and be within the limits shown. As it changes it should be smooth and continuous with no glitches, dropouts or surges.

I use these insulation piercing probes from EZ Hook:



They have stainless steel tips and will easily pierce automotive wire leaving just a small nearly self-sealing hole in the insulation. Use dielectric grease to weatherproof the puncture, or RTV sealant for a more permanent seal...
May 19th, 2013 08:00 PM
dark_horse Not to thread jack but what is the proppwr way to test the tps? Do I disconnect the and test off the pig tail or keep plugged in and expose the wires and test off that?

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May 19th, 2013 04:41 PM
1_nice_03_gt ok thanks cliff, guess i'll give it another try and see what happens
May 19th, 2013 04:25 PM
cliffyk
Quote:
Originally Posted by 1_nice_03_gt View Post
i did not do that n no vacuum leaks
From the shop manual:



Here are the TPS output specs, if you open and close the throttle while observing the TPS output voltage it should follow these tracks. It also needs to be smooth with no dropouts or surges:

May 19th, 2013 04:20 PM
Nitmare67
Quote:
Originally Posted by dark_horse View Post
ive got the exact same problem man...my rpms dont hang when coming down but stops rite at 1500 when rolling but come to stop down to 800rpm...its stupid lol

im going with an oem one soon!
That's exactly how it's supposed to work... That is how the tune is setup.. There is a scaler that sets the min MPH to return to idle which is why your car will hang around 1300 until your under 5mph or a complete stop basically.



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May 19th, 2013 04:17 PM
cliffyk
Quote:
Originally Posted by arummel93 View Post
You guys can't cracks your IACs open and clean them? IAC on my car has at least 300k miles on it. It acts up, I take it apart and clean the carbon out of it, good as new.
It is a crimped assembly--no way to open it up non-destructively...
May 19th, 2013 04:14 PM
1_nice_03_gt
Quote:
Originally Posted by cliffyk View Post
The CX 1808 is the older Hitachi sourced unit, the CX1785 is the newer device supplied by Nippon-Denso.

Did you disconnect the battery for 5-7 minutes during/after installing the new IAC? This is needed to reset the PCM's KAM (Keep Alive Memory) and force it to learn new idle air trim values.

Also make sure the IAC gasket is not leaking, and that you have no other vacuum leaks after the MAF...
i did not do that n no vacuum leaks
May 19th, 2013 04:07 PM
arummel93 You guys can't crack your IACs open and clean them? IAC on my car has at least 300k miles on it. It acts up, I take it apart and clean the carbon out of it, good as new.
May 19th, 2013 04:03 PM
cliffyk The CX 1808 is the older Hitachi sourced unit, the CX1785 is the newer device supplied by Nippon-Denso.

Did you disconnect the battery for 5-7 minutes during/after installing the new IAC? This is needed to reset the PCM's KAM (Keep Alive Memory) and force it to learn new idle air trim values.

Also make sure the IAC gasket is not leaking, and that you have no other vacuum leaks after the MAF...
May 19th, 2013 03:48 PM
1_nice_03_gt
Quote:
Originally Posted by bigjohnstud4200 View Post
Get the Motorcraft from rockauto, I believe it's about 80. I had the Autozone crap and it did the same thing. I swapped it out for another Autozone and it did the same thing but instead of 2200 RPM it was like 1800 or something.
whats the difference between these two:
MOTORCRAFT Part # CX1785 {#2R3E9F715AA, 2R3Z9F715AA, F539E857AA} A


$92.79
MOTORCRAFT Part # CX1808 {#2R3E9F715DA, 2R3Z9F715DA}

---------- Post added at 11:48 AM ---------- Previous post was at 11:47 AM ----------

Quote:
Originally Posted by SSG Pate View Post
You have to remember Cliffy is the exception he is a Mad Engineer Scientist he probally bought one from advance and then turned it into a space shuttle then forgot what he was doing and put his old one back on.
May 19th, 2013 03:24 PM
SSG Pate
Quote:
Originally Posted by 1_nice_03_gt View Post
lol i actually asked about them ( https://www.moddedmustangs.com/forums...ro-valves.html ) cliff is running one for 75k so thought id give them a chance, n well it made the car sound like shit,idle high or die
You have to remember Cliffy is the exception he is a Mad Engineer Scientist he probally bought one from advance and then turned it into a space shuttle then forgot what he was doing and put his old one back on.
May 19th, 2013 03:22 PM
bigjohnstud4200 Get the Motorcraft from rockauto, I believe it's about 80. I had the Autozone crap and it did the same thing. I swapped it out for another Autozone and it did the same thing but instead of 2200 RPM it was like 1800 or something.
May 19th, 2013 03:17 PM
1_nice_03_gt
Quote:
Originally Posted by SSG Pate View Post
LOL shame on you for cheaping out on this, the things we do to save a few dollars!
lol i actually asked about them ( https://www.moddedmustangs.com/forums...ro-valves.html ) cliff is running one for 75k so thought id give them a chance, n well it made the car sound like shit,idle high or die
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