Idle Hanging (Solved) and stupidly simple.


Apr 2, 2019
New Jersey
So, my kid broke down in his 2002 mustang gt last night with a car that was free revving and hanging at over 3k rpms. I couldn’t fix it in the dark so I towed it home. I removed the throttle body TPS, , IAC, and MAF and cleaned thoroughly. I replaced the TPS, IAC, and MAF before I found the real culprit. It was good that I did replace this stuff anyway cause the IAC had a sluggish piston and something was causing the car to be very touchy shifting into first causing bucking. The combination of the three fixes solved the bucking but not the idle

The real culprit was far simpler. The stupid idle screw that is in his 73 MM BBK throttlebody kept unscrewing towards the passenger side when the car was driving due to vibration. This raises the idle. So simple that it took me more than 5 hrs to figure out. After verifying all the other stuff to include vacuum lines weren’t the issue. I put some locktite on the screw and perfect. No more issues. Editted which way the idle screw was moving and took off the zip tie as locktite dried and now it’s perfect without it.

Mods: bama tune, BBK 73MM TB, Full SLP exhaust with LTH, off-road X with HF cats, UDPS, short throw shifter, and a few more goodies
Last edited:
  • Like
Reactions: MattMan02GT
  • Sponsors(?)

Thread starter Similar threads Forum Replies Date
7991LXnSHO Drivetrain New hanging idle problem Fox 5.0 Mustang Tech 7
L High Idle and Hanging RPM. Tried everything, still no fix. SN95 4.6L Mustang Tech 0
darryl paarman After revision - now hanging idle - Digital Self-tuning Forum 30
Onesick99GT Please Help! Datalog Uploaded Hanging Idle Digital Self-tuning Forum 34
L Engine Rough Idle at Start, Possible CMCV Vacuum Leak 2015+ Specific Tech 0
JustMan Engine Hanging Idle After Hard Acceleration SN95 4.6L Mustang Tech 3
N Engine 1987 LX 5.0 5 Speed - idle and . . . Fox 5.0 Mustang Tech 4
Z Hanging Idle + Leaking Brake Proportioning Valve Fox 5.0 Mustang Tech 4
fredfifty Hanging Idle! Anutha One! (dj Khaled Voice) 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 12
C High Idle And Hanging Rpms :( SN95 4.6L Mustang Tech 3
Kabuki_notch Engine High Idle On Startup And Hanging Idle Fox 5.0 Mustang Tech 1
I Surging/ High Hanging Idle Tps Fox 5.0 Mustang Tech 3
theYman Aod To T5 Swap Complete Hanging Idle Fox 5.0 Mustang Tech 12
G Idle Hanging At 1500rpms Fox 5.0 Mustang Tech 3
Shouter The Dreaded Hanging Idle, I Am At My Wits End! Help SN95 4.6L Mustang Tech 19
Blau Surging Rpms, Hanging Idle, Losing My Mind 1994 - 1995 Specific Tech 2
90lxwhite Plz Help. 2 Issues Hanging Idle N Over Heat W Ac 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 1
GT99BLACK High Idle, Hanging Rpms (i Promise I Searched) SN95 4.6L Mustang Tech 18
notch351 hanging idle issue SN95 4.6L Mustang Tech 3
K Idle hanging when shifting? SN95 4.6L Mustang Tech 10
bhuff30 IAC valve - hanging idle SN95 4.6L Mustang Tech 5
larrym1961 WTF hanging high idle AGAIN!!! Fox 5.0 Mustang Tech 7
0 Engine Hanging Idle 2000 Curse After Mod Fox 5.0 Mustang Tech 2
FordRacing302 Hanging Idle, High Idle, Surging, Running Rich Fox 5.0 Mustang Tech 2
xMalignancy High Idle, Hanging Idle!!! Fox 5.0 Mustang Tech 6
JenkinsBS Hanging idle @ 2k then returns to normal Fox 5.0 Mustang Tech 6
JymboSlice idle hangs at 1500 rpm? SN95 4.6L Mustang Tech 26
KHibbs Hanging Idle with Vortec ... I think I'm close Fox 5.0 Mustang Tech 15
5 Idle hangs when coming to a stop SN95 4.6L Mustang Tech 7
I hanging idle or no??? SN95 4.6L Mustang Tech 5
bergs whats up with my tps? hanging idle SN95 4.6L Mustang Tech 0
M High Idle and Hanging Rpms 4.6L Ford Mustang SN95 4.6L Mustang Tech 2
P Hanging Idle 1994 - 1995 Specific Tech 6
OrangeMustangGt hanging idle! 1994 - 1995 Specific Tech 4
LaserSVT 04 GT hanging idle problem. SN95 4.6L Mustang Tech 19
89stang1 hanging idle Fox 5.0 Mustang Tech 2
bobc83 hanging idle after disconnecting battery SN95 4.6L Mustang Tech 9
67coupe Hanging idle returns after cleaning 10pin multiple times!!! Fox 5.0 Mustang Tech 16
SonicStangGT Hanging idle SN95 4.6L Mustang Tech 6
Mr. Rustypwnz hanging idle? wtf 1600rpm!! Fox 5.0 Mustang Tech 9
E Hanging Idle w/new upper intake plenum installed SN95 4.6L Mustang Tech 5
86turbo hanging idle, not iac Fox 5.0 Mustang Tech 4
asecretfile Hanging idle question?? Fox 5.0 Mustang Tech 1
S new throttle body-high idle,and hanging rpm's SN95 4.6L Mustang Tech 15
twogts4us Mach 1 Hanging Idle Special Production 3
RFMustangGT Auto with hanging idle.. 1994 - 1995 Specific Tech 4
2000fordstanggt hanging idle only after reaching operating temp SN95 4.6L Mustang Tech 4
yomadmike BBK tb, hanging idle SVT Tech Forum 1
94opalgt idle started hanging up 1994 - 1995 Specific Tech 8
F Idle hanging up? 1994 - 1995 Specific Tech 12
Similar threads