• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

code keeps comming back help

  • Thread starter Thread starter mat82284
  • Start date Start date Sep 25, 2005
M

mat82284

Member
Jul 31, 2003
889
1
16
Sep 25, 2005
#1
  • Sep 25, 2005
  • #1
ok i pulled codes a wile back and got this P1506 and then i reset the computer and it still back. how do i know if my iac is bad? i just got a new tps and its set to .99 since i cant get it any loser and the screw hols are ported. how do i test the iac? when i pulled the black hose off of it it idled the same no change. but when i steped on the gas the rps didnt hang anymore like it did when it was on. what would cause this and how do i fix it? also my car still idles at 1400 when in nutral but drops to 1000 when i am at a stop. ( i added a 70mm tb and plenum)



P1506-Idle Air Control Overspeed Error
 
M

mat82284

Member
Jul 31, 2003
889
1
16
Sep 25, 2005
#2
  • Sep 25, 2005
  • #2
ok another question i unpluged the iac and it idles at 900 rpms at a stop and when im moving it idles at 1100 which is better than when its connected. does this mean i have a vacume leak? what can i spray to check for leaks? theres a piece behind the C&L plenum that connects to a hose and when unpluged the car sounds like it has a cam and almost dies is this normal? where does that hose lead? whats it for?

 

53BigDog

Active Member
May 22, 2001
2,331
0
47
Palm Harbor, FL
Sep 25, 2005
#3
  • Sep 25, 2005
  • #3
I believe it is your emission control vacuum tube. I sholud be a black and red vacuum line. I would also suggest resetting your computer by disconnecting the batt cable for 10+ minutes. Then upon start up let your car idle for 4-6 minutes before ding anything to it (driving, revving, etc) let the computer recomplie the idle data. Try that....and let me know
 
M

mat82284

Member
Jul 31, 2003
889
1
16
Sep 25, 2005
#4
  • Sep 25, 2005
  • #4
53BigDog said:
I believe it is your emission control vacuum tube. I sholud be a black and red vacuum line. I would also suggest resetting your computer by disconnecting the batt cable for 10+ minutes. Then upon start up let your car idle for 4-6 minutes before ding anything to it (driving, revving, etc) let the computer recomplie the idle data. Try that....and let me know
Click to expand...

thats not the black and red line thats the one on the front of the plenum and the on i maked in red on the pic is for the back of the plenum. im trying the reseting and learning thing. ill let you know in about 15mins
 
M

mat82284

Member
Jul 31, 2003
889
1
16
Sep 25, 2005
#5
  • Sep 25, 2005
  • #5
thats a negative. it didnt work. it does how ever idle higher now it idles at 1600. is it possible to drive without the pcv pluged in? is this happening because of a leak? how do i check for leaks?
 

53BigDog

Active Member
May 22, 2001
2,331
0
47
Palm Harbor, FL
Sep 26, 2005
#6
  • Sep 26, 2005
  • #6
Feel around and wiggle some of the hoses see if you can hear any suction. Follow all hoses from the top intake and see if there are any plastic couplings or hoses cracked. Did you try replacing your IAC?
 
M

mat82284

Member
Jul 31, 2003
889
1
16
Sep 26, 2005
#7
  • Sep 26, 2005
  • #7
53BigDog said:
Feel around and wiggle some of the hoses see if you can hear any suction. Follow all hoses from the top intake and see if there are any plastic couplings or hoses cracked. Did you try replacing your IAC?
Click to expand...

i was going to but i heard that if you unplug the iac and block the hose off and let the car idle and if it dies then the iac is good. but my car idles at 900 when its unpluged and it should die so that rules out the iac cause the iac cant be adding air. now when its pluged in it idles at 1400 cold and 1600 worm. ill have to check the hoses. if i had a leak then this would happen right? how do i check for leaks arround the intake? what can i use?
 
You must log in or register to reply here.

Similar threads

A
Rough idle - cylinder 1 and 6 misfire HELP
  • austindavies935
  • Jul 24, 2025
  • SN95 4.6L Mustang Tech
Replies
12
Views
632
SN95 4.6L Mustang Tech Jul 24, 2025
gkomo
F
Help with air bag code 2293
  • Felwinters
  • Apr 23, 2026
  • 2005 - 2009 Specific Tech
Replies
0
Views
48
2005 - 2009 Specific Tech Apr 23, 2026
Felwinters
F
K
Engine 2000 Mustang GT - Fuel issue post-blown spark plug repair
  • kenster1092
  • Feb 26, 2026
  • SN95 4.6L Mustang Tech
Replies
4
Views
283
SN95 4.6L Mustang Tech Mar 10, 2026
kenster1092
K
C
Engine Idle cuts out
  • claypoolxx
  • Mar 7, 2026
  • Fox 5.0 Mustang Tech
  • 2
Replies
20
Views
459
Fox 5.0 Mustang Tech Saturday at 5:11 PM
alutwon
SURGING IDLE / NO IDLE CHECKLIST FOR 1996–1998 MUSTANG GT (4.6L 2V) - Work In Progress
  • Noobz347
  • Aug 30, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
644
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?