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Discussion Starter · #1 ·
Hi.

I was suffering with an uneven idle on my 2006 GT when I turned on the AC so I very carefully cleaned the MAF & throttle body with CRC products.

MAF looked clean (but probably difficult to tell) & throttle body was very dirty.

After reassembling everything when I started the engine it shot up to about 3000rpm & then hung at whatever RPM I changed gear at (it is a 5-speed).

I have disconnected the battery overnight to try & 're-set' the engine management system.

Now when started it revs to 2000 rpm (which seem a bit high for a cold engine) & then slowly falls to about 1000 rpm (takes about 20 seconds & I'm guessing that this is since it is cold). When hot it does the same but eventually falls to about 800 rpm.

The revs seem to hang a bit when changing gear & it takes longer for the revs to fall back down when stopped in neutral (dropping initially to 1000 rpm & then down to about 750). The othing that have noticied is that when I turn the engine off, the rev-counter needle takes a while to fall back to zero (even though the engine has stopped).

I have a drop in K&N air filter, but other than that the car is stock.

Previously (before cleaning the MAF & TB) when starting revs would jump to 1500 & fall back quickly. Also revs would fall quickly between gear changes, & the rev counter would drop quickly when the engine was turned off.

My gut feeling is that something isn't right after cleaning the MAF & TB, but maybe everything is OK & I'm just not used to how the car is supposed to act.

Can anyone let me know if it is running as it should be & if not any suggestions as to what needs to be done to make it run as it should.

Thanks very much!
 

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When you cleaned the throttle body did you take it off the car? I had similar problems with mine,when I cleaned the maf and throttle body. I ended up re doing it by taking the throttle body off and giving it a real good cleaning with the spray. There was some very small grit that was hanging up the butterfly..Good luck.:bigthumbsup
 

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Have you cleaned the MAF sensor also?
 

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Have you cleaned the MAF sensor also?
Yep that is what I was going to ask? I clean mine with MAF sensor cleaner. Reminds me I got to go and get some.
 

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Discussion Starter · #6 ·
I cleaned both the MAF & throttle body off the vehicle.

Throttle body felt like it was seated properly when I re-installed it, but I'll check to make sure that the TB is correctly fitted to the intake.

Thanks.
 

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Discussion Starter · #8 ·
Took the throttle body off & cleaned it again.

This time I made sure that the gasket stuck out further from the intake & tightended up the throttle body diagonally to try & prevent any warping & get a good seal.

Couldn't find the torque specs in the Chilton manual so just tightened up the nuts/bolts by feel - Anyone know the torque setting for the throttle body to intake nuts/bolts?

Seems to run better (revs still hang slightly, but come down much quicker when starting). Maybe the gasket wasn't sealing properly?

Thanks
 

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One more thought... Could you have bumped the throttle position sensor when you took the throttle body off? Those things are very sensitive. Might want to check your TPS voltage with a voltmeter. Probe the bottom (yellow) wire with key on/engine off and it should read between 1.19 and 1.31 volts. The closer you are to 1.25 the better. If it's way high or low you can try to adjust by loosening the scews and manipulating the TPS up or down while checking the voltage and then retighten when you reach the desired voltage. If that doesn't work, it could be time for a new TPS (~$50 from Ford).
 

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An easy thing to check is if any of the hoses that are attached to your air box came loose when you were moving stuff around. If they come loose or dont have a tight seal, some of them start to fill up with oil and leak and make your car idle funny.
 

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Im getting a little of subject but,
For the CRC Throttle body cleaner why does it say not to use on a supercharged engine on the bottle? I know they probably mean factory blower. STL Wagon? I have a bottle and am gonna clean my throttle body but was wondering why the bottle said this.
 

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Im getting a little of subject but,
For the CRC Throttle body cleaner why does it say not to use on a supercharged engine on the bottle? I know they probably mean factory blower. STL Wagon? I have a bottle and am gonna clean my throttle body but was wondering why the bottle said this.
I have no clue unless it could damage gaskets or bearings. I'll have to look into this more.
 

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Discussion Starter · #17 ·
I'll check the TPS.

I was very careful when removing the TB & MAF but you never know. These days it seems that just the slightest knock or just taking something apart seems to affect these ultra-sensitive electronics.

Thanks for the torque setting.
 

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I had the same exact issue with the throttle hanging after releasing the gas. It was like cruise controll on the highway almose. In fact, when comming to a stop the RPM's never went below like 1100. Also when revving the engine the RPM's would go down and than back up again.

The solution: I brought it to the dealer and they reflashed the computer.. Cost me 100.00 but it worked. If you have your own tune maybe you can try that.
 

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Discussion Starter · #20 ·
The car needed a service anyway, so also had the computer re-flashed at a local dealer ($60).

All specs are, apparently, within acceptable limits, but it hasn't really made that much difference :(
 
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