• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

1981 high idle after 1 barrel carb change

  • Thread starter Thread starter Mark B.
  • Start date Start date Nov 30, 2018
M

Mark B.

New Member
Nov 30, 2018
5
1
1
Hopkinsville, KY
Nov 30, 2018
#1
  • Nov 30, 2018
  • #1
I'm hoping someone can lend me some guidance. I have a 1981 mustang with a 3.3L inline 6. i recently changed the old 1 barrel carb out for a new 1 barrel carb. The connection went fine. When i started the car it idled straight up to 2100 RPM's and doesn't calm down. All vacuums are plugged into where i think they are supposed to go. Does anyone know of a vacuum diagram for the inline 6 with single barrel carb application? Any advise would be greatly appreciated.
 

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
5,816
213
Nov 30, 2018
#2
  • Nov 30, 2018
  • #2
Is there an idle screw adjustment on the linkage ? Have you tried turning it down manually ?
 

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
3,438
1,525
194
Maryland
Nov 30, 2018
#3
  • Nov 30, 2018
  • #3
Choke may need adjusting or maybe the high idle cam is stuck and not dropping. Sometimes you have to slam the throttle to the floor for a quick instant to back it down after the initial start.
 
M

Mark B.

New Member
Nov 30, 2018
5
1
1
Hopkinsville, KY
Dec 4, 2018
#4
  • Dec 4, 2018
  • #4
90sickfox said:
Is there an idle screw adjustment on the linkage ? Have you tried turning it down manually ?
Click to expand...
that's one of the first things I tried with it being a new carb. Turns out atleast part of it is a vacuum leak at the carb base. I got a new gasket that I hope will fix all the issues. Thanks for the suggestion.
 
Reactions: 90sickfox
M

Mark B.

New Member
Nov 30, 2018
5
1
1
Hopkinsville, KY
Dec 4, 2018
#5
  • Dec 4, 2018
  • #5
John Dirks Jr said:
Choke may need adjusting or maybe the high idle cam is stuck and not dropping. Sometimes you have to slam the throttle to the floor for a quick instant to back it down after the initial start.
Click to expand...
thanks for the advise. I found a vacuum leak at the base of the carb after I posted that. Got a new gasket hopefully that will fix it. If not I'll check your suggestions. Thanks again.
 
You must log in or register to reply here.

Similar threads

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
736
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
SURGING IDLE / NO IDLE CHECKLIST FOR 1999–2004 MUSTANG GT (4.6L 2V) - Work In Progress
  • Noobz347
  • Aug 30, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
902
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
R
94’ SN95 - Intermittent lope & bogging at moderate rpm
  • Red5.0ho
  • Nov 2, 2025
  • 1994 - 1995 Specific Tech
Replies
5
Views
460
1994 - 1995 Specific Tech Nov 3, 2025
General karthief
G
2006 Mustang GT o2 Sensor Wiring Issue Car Bogging/Choking
  • GCantero93
  • Sep 5, 2025
  • 2005 - 2009 Specific Tech
Replies
4
Views
1K
2005 - 2009 Specific Tech Sep 6, 2025
Noobz347
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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?