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Discussion Starter #1
Hey FF,

Well so this all started cause I had to replace a stuck open thermostat and in the process the intake manifold had to come out... so might as well clean the manifold intake out and replace the PCV valve which was probably overdue in the process right? [wrenchin] And as I feared, me trying to do right by the car has lead to more issues to deal with.

After putting everything back together the car now idles crazy high, as high as 3500 rpm for the first few seconds then it drops to a steady 2000 rpm. But for me the idle was between 800-1000 normally beforehand.

I took out all the electronics from the manifold (IAC valve, MAPT sensor, the swirl flaps actuator and the throttle body + throttle position sensor). I let the the manifold soak for a while in a degreaser solution and blew it out with a leaf blower and pressurized air hose. I inspected the swirl flaps which I've seen have been a problem for some people but there's no wiggle in them at all. The manifold was left to dry throughly before I but everything back on. The manifold gaskets looked fine so I did not replace them. (they were $40 from the dealer [???:)] so I'd like to return those...

Now Im really trying to figure out why my idle speed is so damn high. My best idea is the throttle position sensor got misaligned. I'll try playing around with that tomorrow.

This is a 2.0 Duratec HE on a 07 ZX4 SES

Does anyone out there have an ultraguage or similar? I get a absolute throttle positon sensor reading of 18% at fully closed throttle. It's probably not gonna to be 0% but prehaps it's bumped up slightly? Any other ideas what I could have done?

I need my baby back! [:(]
 

w/ my magic bag
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I'd think its the tps too...Should of left it on the tb. Hopefully you replaced the pcv hose? I used a dorman over the motorcraft one.
 

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Discussion Starter #3
The throttle position readings seem normal to me. 18% to 93% at WOT. I would have figured if it was set higher than when I pressed on the pedal I'd get abnormally high readings but 93% as max seems normal.
 

Old Phart
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Moved to General Tech Chat, repair not perf. mod. questions.

Yes, those are typical TPS readings.

Vacuum leak is your first suspect, how do the fuel correction readings look?
 

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Ford says any TPS around 20% is essentially at zero, 18 is fine.

Now you know just why you do NOT reuse any gaskets there; you have a vacuum leak. 90% of the fast idle faults here onsite are from that mistake. The gaskets look fine but they have lost crush and no way can you get that back.

If you didn't change the pcv HOSE while in there......................a big mistake.
 

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Discussion Starter #6
Problem resolved! [thumb] A big thanks for everyone who commented in. It's was nice to feel the support on here when I ran into trouble.

So I removed the throttle body plate for cleaning by unscrewing the 2 torx screws and sliding it out from the metal rod. And when it came time to put it back in I reinstalled the throttle plate UPSIDE DOWN!. I know, I know... how stupid! The wedge side goes on the bottom facing in towards the manifold. Look up a picture of it and you'll see what I mean. After moving that the correct way, the engine now idles as it has before [:)]


Also, worth mentioning for anyone finding themselves with a similar problem:

If you have an ultraguage or similar OBDII tool, and you can get the Manifold Absolute Pressure reading. You can use that to do a Intake Manifold Vacuum Test as described in my focus workshop manual (pg. 303-00-11)

With engine off, my MAP reading is 93 kPa (which is the exact same reading my smartphone gives so I know that reading is good). The manual reports vacuum gauge should read between 51-74 kPa depending on engine condition and altitude. Subtract 4.0193 kPa for every 1,000 ft above sea level.

In my case, I'm 鈮1,637 above sea level where I'm at, subtracting 6.5795941 gives me a range from 44.4-67.4. My readings immediately after startup where 43-45 and fairly steady so it seems about right.
 

Old Phart
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Thanks for posting the resolution! Could help someone else besides satisfying our curiosity.

Answer was in the missing info. from the first post I'm afraid, no mention of fiddling with the throttle plate!

Nice to hear you figured it out.
 

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Thanks for sharing info about MAP/Vac test info. Last time I looked at mine (a year ago) it ran higher than yours. I live at 1,700 ft. I had my scan tool set to use inHg instead of kPa. Mine idles at about 18 inHg, while yours is about 13.

...The wedge side goes on the bottom facing in towards the manifold...
Going off a vague memory (about a year+ ago) I could almost swear the wedge faces the inlet, is not facing towards the manifold. Hmmm...?? Maybe I will re-visit this later.
 

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...
Going off a vague memory (about a year+ ago) I could almost swear the wedge faces the inlet, is not facing towards the manifold. Hmmm...?? Maybe I will re-visit this later.
Bad memory. I looked around online and found you are correct, wedge faces towards the manifold. Sorry about that.

I also now wondering if my 2004 2.3 engine throttle plate might have a slightly different design. Hmmm???
 

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Unless a really thin one the edge chamfer angle will commonly tell you which way it goes in, some are not centered on the shaft either, it makes them tend to self close as a safety thing.

Thanks go to the OP for having the balls to mention the mistake, personally hard to do but helpful to others and mainly himself as it is proof he looks at his own work.

10 claps of the hand for that one, the mark of a better worker.
 
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