4.9 rough idle
Postmaster
Joined: Oct 2006
Posts: 4,816
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From: Davis & Newcastle, CA
Originally Posted by netscaner
Although it may not be the cause of his particular problem, a stuck open or unable to close all the way EGR will DEFINATELY cause a very rough idle. The EGR is supposed to be fully closed at idle, and opened at it's max during normal cruise, then tapering off slightly during high acceleration low vacuum situations.
-Chris
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Senior User
Joined: May 2007
Posts: 101
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From: Auburn, California
ok so i cleaned out the IAC in hopes that just cleaning it might work then i took apart the throttle body and noticed a warning label saying not to spray anything into it because it is coated with some special coating. So all i have to do now i guess before i go get a new IAC or EGR is flush out the injectors. I am thinking that i will buy like 5 things of the unconcentrated cleaner and put in like 5 gallons of gas and then hope that does the trick. oh, Netscaner, do you mean IAC? because the EGR is not bolted directly to the intake manafold.
Postmaster
Joined: Oct 2006
Posts: 4,816
Likes: 1
From: Davis & Newcastle, CA
Well I don't know about the 300, but on the 351 (and I believe the 302) the EGR bolts to the intake manifold. And the warning on the throttle body is not really true (to an extent). Almost all the guys on this forum have cleaned out their TB with no bad effects on the truck. But you don't need to take it apart and scrub it if you don't want (if so, more power to you). An easy, and probably a bit let effective way, to clean the TB, is to suck half a can of Seafoam into the break booster line. Let the truck choke and die, if it doesn't turn it off. Let it sit for 15-20 minutes. Fire it back up and watch the smoke fly. Be careful about doing this in residential areas as it will alarm any onlookers. See here when I did mine:
http://video.google.com/videoplay?do...q=seafoam+ford
Good luck!
-Chris
http://video.google.com/videoplay?do...q=seafoam+ford
Good luck!
-Chris
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