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Discussion Starter #1
Ok, so I did a search, but nothing specific to the Duratec..

I'm having a problem where when I let off the gas at a stoplight, the revs drop to 2000RPM then hang there for a few seconds, before slowly dropping to 800RPM, then a slight bump back up to 950RPM or so.

Initially, I thought there must be a vacuum leak somewhere, but I can find anything that seems to be leaking anywhere.

The throttle cable does not seem to be binding, I sprayed some Kroil in the cable sheath and loosened things up, same idle problem.

Anyone have any ideas?
 

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Vacuum leaks on EFI cars tend to cause low idle conditions not high idle. A vacuum leak on a carbed vehicle causes high idle conditions, which is where the confusion comes in.

I suggest cleaning the IAC with carb cleaner and then re-installing it. If you have a manual transmission and you are shifting into neutral to coast to a stopping point, then hanging idle is not uncommon. The PCM senses that the vehicle is still moving through the VSS, and maintains a higher idle that will facilitate easier shifting. As soon as the vehicle stops, the idle drops. My car does this, but not as high as 2k rpm regularly. I'm not sure how the PCM figures where to hold idle speed, but it might have to do with how fast the engine was turning in gear before you shift into N.
 

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Discussion Starter #3
I'm not arguing, but it's been my experience (with Bosch Motronic anyway) that vacuum leaks cause high and/or surging idle.

Of course, I've never had to do ANYTHING to the EFI on this car for over 90,000 miles =). It's been a great daily driver. The idle hanging at 2000RPM is something new.

I assume the IAC is an idle control valve? Where is it located?
 

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IAC= idle air control valve. On a Duratec it's located just behind the TB. Looks like this


Actually, I don't think it has that button thing on the top of it. The picture is of a generic Ford IAC, not one from a Dtec specifically.
 

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OH, you'll see 2 chambers, and there might be a gasket. If there is not a gasket, you can purchase one for like $1 if it makes you feel better. You shouldn't have to use one though. I'd clean the shaft with a Q-tip after spraying it with carb cleaner, and work the plunger with the Q-tip. It should move easily. If you see any damage to the plunger, that might help explain the problem. You'll have to replace the IAC in this case.
 

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If I remember a couple of people have had idle issues related to the alt wiring as well as intermittent radio problems only.
 

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That is possible. Alternators are very difficult to remove from these vehicles. You must separate the axle from the hub, and move it out of the way. This means disconnecting the steering, and possibly the end link. You might even need a 2 jaw gear puller to push the axle out of the hub if it's stuck. That will require removing the caliper mount bracket, and hanging the caliper and mount off to the side.

You should also double check continuity between the positive battery terminal and the main hot to the alternator just to be sure there is no wiring damage.

I highly suggest that you remove the alternator and then look in the yellow pages for a local rebuilder. 2 things regularly go bad on alternators: bearings and voltage regulators. The magnets and copper windings never go bad. Anyway, typical local rebuilder price is $40-80. You might have to catch a ride, and it might take a day for it to be rebuilt as well as some time to locate the rebuilder. Compared to $200 for an alternator- it's worth it if you can stand to bum a ride.
 

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Discussion Starter #10
Problem solved. The new alternator cured the idle problem. Maybe not enough voltage to the ICV?

There is NO need to remove the axle to remove the alternator nor is it a difficult job.
The key to removal is to remove the two mounting studs that hold the alternator to the back of the block, then simply remove the alternator up from behind the engine. takes about an hour to swap it out.

I figure the axle removal way is out of a Ford technical service book in order to pad the hours for labor. I called my local dealer (South Bay Ford) with my VIN to get the part number for the alternator. Well, they wouldnt give me it. They quoted me $482 for a new one and $1200 to replace it.

I went down to Rotex (local rebuilder in Gardena, CA), they had it rebuilt with warranty in four hours for $140. Slapped it back in and the car runs like a champ now.
 

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I have a problem. Got a 2007 focus 2 xr5 turbo. The car is missing. I have checked the plugs and they are ok. Checked all coils and found number 3 does not do anything ,so i thought it must be the coil replaced with a nother one still doing same thing . Any sugestions please
 

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Being that you have an engine most are not familiar with it will be difficult but we can help. Please create your own thread as this one is not related.
 
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