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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech

idle started hanging up

  • Thread starter Thread starter 94opalgt
  • Start date Start date Aug 12, 2007

94opalgt

Member
May 5, 2005
358
0
17
AKRON,OHIO
Aug 12, 2007
#1
  • Aug 12, 2007
  • #1
on our way to the mustang show at summit last weekend. car starts hanging the idle at 1500rpm. now, it dont do it all the time. when we left summit it didn't do it. got in the car later that evening, did it again. i'm thinking tps or maybe the meter. any help here?
 
F

Fopar

Member
Apr 1, 2007
178
0
16
San Marcos, CA
Aug 12, 2007
#2
  • Aug 12, 2007
  • #2
could be TPS, but since intermittent i'd say IAC
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Aug 12, 2007
#3
  • Aug 12, 2007
  • #3
Does shutting the car off and back on make it fix itself for a little bit? If so, think TPS.

If not, the IAC idea is a good one. When the IAC hangs up, you can see some hot-idle surging as well.

Good luck.
 

94opalgt

Member
May 5, 2005
358
0
17
AKRON,OHIO
Aug 12, 2007
#4
  • Aug 12, 2007
  • #4
if i shut the car off and start it again, the idle goes back to normal. till i drive it again and it starts hanging up again. it's not surging at all, it just sticks. or if it comes down to like 1100-1200rpm it will climb up to 1500-1600rpm by itself.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Aug 12, 2007
#5
  • Aug 12, 2007
  • #5
Though it might not be your case, that's a sign of a bad TPS. If you have a spare or one from a buddy's car, I'd try swapping it out.

Good luck.
 

94opalgt

Member
May 5, 2005
358
0
17
AKRON,OHIO
Aug 13, 2007
#6
  • Aug 13, 2007
  • #6
allright, found the iac screw all the way in. backed it out 1 1/2 turns, took the car out, idle still hangs up. but now it's different, i hangs at 1600-1700rpm till the car comes to a complete stop, then drops to where it should be. i'm gonna swap the tps from my coupe and see what happens.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Aug 14, 2007
#7
  • Aug 14, 2007
  • #7
Your rolling idle should hang at around 1200-1500 RPM from the factory. This is done so the car doesn't stall while you use PS, brakes, etc but are otherwise at idle.
 

1TallMF

New Member
Apr 17, 2006
955
1
0
Montreal
Aug 14, 2007
#8
  • Aug 14, 2007
  • #8
Mine randomly started doing that a while back, then I decided to take-off the IAC and clean it. It was caked in carbon crap, so I guess it was just sticking. The car has been idling perfectly ever since.
Edit: BTW the bottom screw is a b^%$# to get to, unless you already have an intake spacer on there or something.
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Aug 14, 2007
#9
  • Aug 14, 2007
  • #9
1TallMF said:
Mine randomly started doing that a while back, then I decided to take-off the IAC and clean it. It was caked in carbon crap, so I guess it was just sticking. The car has been idling perfectly ever since.
Edit: BTW the bottom screw is a b^%$# to get to, unless you already have an intake spacer on there or something.
Click to expand...

I also say to give it a good cleaning

I'd keep the screw at 1 1/2 turns

Reset the pcm

Give it a couple of days to gather enough data to make sufficient adjustments

If not stable ... back it out 1/4 more turn and wait a couple more days

The key is to give the pcm enough time do its thing

You just find the best setting your car likes

Grady
 
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