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  • 1965 - 1973 Classic Mustangs -General/Talk-
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idle drops off at stop lights

  • Thread starter Thread starter Kurt
  • Start date Start date Jul 13, 2005
K

Kurt

Founding Member
Feb 12, 2001
149
0
0
South Hill ,Va
Jul 13, 2005
#1
  • Jul 13, 2005
  • #1
When i have the car in gear the idle will start to drop of (lobe down, gradually decrease) and then cut off. the car will idel fine in park. what are some areas to look at.
Timming ?
vacum leak?
head gasket?
please direct

Kurt
 
K

Kurt

Founding Member
Feb 12, 2001
149
0
0
South Hill ,Va
Jul 13, 2005
#2
  • Jul 13, 2005
  • #2
1973 351c c6
 

krash kendall

Active Member
Nov 19, 2004
1,258
0
36
Aldergrove, B.C. Canada
Jul 13, 2005
#3
  • Jul 13, 2005
  • #3
Fuel delivery.
 
K

Kurt

Founding Member
Feb 12, 2001
149
0
0
South Hill ,Va
Jul 13, 2005
#4
  • Jul 13, 2005
  • #4
so fuel filter would be first thing to check
 
G

grego37

New Member
May 12, 2004
576
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0
Fresno CA
Jul 13, 2005
#5
  • Jul 13, 2005
  • #5
Id say double check/adjust timing,
then focus on the carb.
idle circuit
air/fuel mixture
look for vacuum leaks
 

2nd Mustang

Founding Member
Feb 24, 2002
2,488
0
46
Southern California
Jul 13, 2005
#6
  • Jul 13, 2005
  • #6
Idles fine in park but not in gear? I'd say check idle speed.
 

pabear89

Active Member
Apr 15, 2003
2,126
0
46
High in the Hills of So Ca with the Voices in My H
Jul 13, 2005
#7
  • Jul 13, 2005
  • #7
Depends on what its doing,
is it loading up?......running rich and flooding out.
Is it hard to restart?
or does it restart with a slight turn of the key.

Off the wall guess.....search for a small vac leak.

PB
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 14, 2005
#8
  • Jul 14, 2005
  • #8
His problem is the reason Ford installed the "Dash-Pot" on the Autolite carbs.
 

pabear89

Active Member
Apr 15, 2003
2,126
0
46
High in the Hills of So Ca with the Voices in My H
Jul 14, 2005
#9
  • Jul 14, 2005
  • #9
Yes and some were for Emissions also.
to let the throttle return slowly to idle to reduce emissions(BS)

And they have ones that increase idle speed for Acc when switched on.
From his symptoms of falling off idle, A vacume leak is where I would start to look.

PB
 

whwright

Member
Jun 3, 2003
150
0
16
Oklahoma City
Jul 14, 2005
#10
  • Jul 14, 2005
  • #10
What kink of carb are you running? My first guess is that the idle mixture is too lean. That does strange things to the vacuum signal, which (on my cars anyway) makes the vacuum advance start to back off, which eventually lowers the idle speed enough to kill the engine.
 
K

Kurt

Founding Member
Feb 12, 2001
149
0
0
South Hill ,Va
Jul 15, 2005
#11
  • Jul 15, 2005
  • #11
A little history I put to much silicone on the intake gasket causing the end seals to push out and I knew there was a vacum/ oil leak, so i fixed that and then posted thread, because the problem continuned.
I then replaced the spark plug wires as well as coil wire, when I removed the coil wire it broke of in the coil. I don't know why but afteri put the new wires on the problem went away.
 

whwright

Member
Jun 3, 2003
150
0
16
Oklahoma City
Jul 15, 2005
#12
  • Jul 15, 2005
  • #12
Glad you got it fixed!

Wayne.
 
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