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idle problem

  • Thread starter Thread starter pimpstang18
  • Start date Start date Jul 13, 2005
P

pimpstang18

New Member
Sep 22, 2004
43
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0
FL
Jul 13, 2005
#1
  • Jul 13, 2005
  • #1
i've got a 2003 gt with all the basic bolt ons, intake,tb,maf,exahust,etc. pretty much everything to help airflow, plus a predator tuner. the car had been running great aside from idleing a little high (about 1200 rpm) every once in a while, this started after i installed my 70mm throttlebody. i went out to the track recently and made a few hard runs and ever since then it does not idle correctly, every time i come to a stop the idle gets stuck from about 1200 to 1500 rpm and i have to rev to engine past 3000 to get it to drop back down to 700 rpm. this happens more often with my a/c on. i am suspecting a faulty tps sensor but i'm not sure, does anyone have any input on what might be my problem? also i have scanned it for trouble codes with my predator but it's not showing any codes. thanks.
 

Lons2001GT

New Member
Nov 16, 2003
75
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0
Jul 13, 2005
#2
  • Jul 13, 2005
  • #2
I have an accufab 70mm and mine did the same crap. If you have an accufab, take it back off and turn it upside down. If there is a screw on the bottom of the tb then screw it all the way in. I was told to do this by accufab and it fixed my problem. If it is not an accufab or there is no screw there, then it may be a miss adjusted tps. Turn the car on and loosen the screws on the tps, gently twist the tps to the left or right depending on how it affects the idle. When the car is idling correctly tighten the screws. Hope this helps.
 

twogts4us

15 Year Member
Apr 1, 2004
4,188
12
79
Dunedin, FL
Jul 13, 2005
#3
  • Jul 13, 2005
  • #3
More likely the IAC, but it could be the TPS. The MAF isn't help the situation - you should really go back to the OEM MAF, which is good for 400 HP. (Been there, done that myself with both Mustangs...OEM MAFs back in both)
The TB (and I presume by intake you mean you added an intake elbow or plenum) - this almost always causes the hanging idle you are describing. Reset your computer by disconnecting the neg batt cable for 10-15 mins, then reconnect and verify that it has been reset by clicking your key forward until you see all the gauges peg and then fall back to zero. This will tell you it has been reset. Then give it a week of normal driving and you should see a 90% improvement in the hanging idle issue.
Welcome to StangNet!
 

04gtdrop

New Member
Jun 10, 2005
532
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Sac, CA
Jul 14, 2005
#4
  • Jul 14, 2005
  • #4
could be your TPS or an issue with the IAC, what kind of T/B is it? accufab, mac, bbk? etc etc....
 
P

pimpstang18

New Member
Sep 22, 2004
43
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0
FL
Jul 15, 2005
#5
  • Jul 15, 2005
  • #5
it's a accufab 70mm tb. thanks for the input guys, i've got to work all weekend but after the weekend i will try those sugestions and let you know if they worked.
 

BooWFO

New Member
May 10, 2005
991
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0
Louisville, KY
Jul 15, 2005
#6
  • Jul 15, 2005
  • #6
Ok stupid ? time doesn't the predator allow you to raise or lower idle?
Also hanging idle have you tried the IAC block off? (I couldn't stand the hangin rpms)
Most likely it is the TPS though the best is to adjust to as close to 1.0v as you can get with out going over 1.0v.
 
2

281Ponies

New Member
Nov 14, 2003
190
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0
Jul 15, 2005
#7
  • Jul 15, 2005
  • #7
Just incase you haven’t checked this, are you sure the throttle cable (linkage) isn’t hanging up on the vacuum line coming off the back of the plenum? I needed a few flat washers to raise the linkage bracket that bolts to the top of the plenum so it did not hang on this vacuum line.

I would go back to the stock MAF, check the TPS voltage and reset the computer.

Good luck with it,
-Cale
 
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