RPMs wont go down!!
03-11-2008, 04:23 PM
#1
1st Gear Member
Thread Starter
Join Date: Feb 2008
Location: Illinois
Posts: 54
RPMs wont go down!!
on my 98 gt, when i rev it up it takes forever for the rpms to drop back down. iv noticed when im drivign down the road, my rpms are higher than normal then after a few seconds they drop back down.i have no clue wats wrong with it. please help!
03-11-2008, 04:33 PM
#2
3rd Gear Member
Join Date: Dec 2005
Location:
Posts: 762
RE: RPMs wont go down!!
Idle air controller might be gummed up, But i would run some injector cleaner through it and replace the fuel filter. the cumputer trys to cut the fuel back and it see's that when it does it too fast the car drops below set idle rpm and it learns it needs to do it slow. It's what mine did. and there are several post on here about this same thing.
03-11-2008, 04:41 PM
#3
1st Gear Member
Join Date: Mar 2008
Location:
Posts: 81
RE: RPMs wont go down!!
2nd on the Idle air sensor. All of them need changed after about 50,000 miles. Also once it is running at idle, look at the tach and see if it is jumping a little bit, if so jerk that thing off and replace it for about $50 or $60 bucks.
03-12-2008, 12:46 AM
#7
2nd Gear Member
Join Date: Nov 2007
Location: Saginaw, Michigan
Posts: 370
RE: RPMs wont go down!!
https://mustangforums.com/m_2625353/tm.htm
DO IT SON, but your gonna lose your high idle during a cold start.
DO IT SON, but your gonna lose your high idle during a cold start.
03-12-2008, 03:32 AM
#8
aka 'Negative Nancy'
Join Date: Jul 2007
Location: Ohio
Posts: 4,839
03-12-2008, 11:17 PM
#10
2nd Gear Member
Join Date: Nov 2007
Location: Saginaw, Michigan
Posts: 370
RE: RPMs wont go down!!
You haven't messed with the idle screw have you? and make sure the iac is still plugged in ok. pull it off the car and if you see carbon gummed up inside it should be replaced.