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

Vents cut out when accelerating

  • Thread starter Thread starter GT40 2
  • Start date Start date Jul 24, 2008
  • 1
  • 2
Next
1 of 2 Next Last

GT40 2

Member
Oct 13, 2004
109
0
17
Jul 24, 2008
#1
  • Jul 24, 2008
  • #1
The air vents stop blowing and blow through the defrost. So I replaced the vaccum motor that controls the panel vents. But it still blows through the defrost. Does anyone have any idea what I should try replacing next?
 

2BADSTANGS

Member
Jun 19, 2008
385
1
18
Colorado
Jul 24, 2008
#2
  • Jul 24, 2008
  • #2
Check all your vacuum lines make sure there isn't a leak. If you dont find anything wrong there check the selector switch amd make sure it seals and changes as it should.
 
R

RustBucket

New Member
Jun 8, 2003
585
0
0
Buford, GA
Jul 25, 2008
#3
  • Jul 25, 2008
  • #3
There's a vacuum check valve that's failed. I can't tell you where it is because I've yet to change one on a Mustang
 

2BADSTANGS

Member
Jun 19, 2008
385
1
18
Colorado
Jul 26, 2008
#4
  • Jul 26, 2008
  • #4
On my '93 Gt the vacuum valves are on the rear of the passenger strut tower.
 

GT40 2

Member
Oct 13, 2004
109
0
17
Jul 26, 2008
#5
  • Jul 26, 2008
  • #5
What do the vacuum check valves look like?
 

GT40 2

Member
Oct 13, 2004
109
0
17
Jul 30, 2008
#6
  • Jul 30, 2008
  • #6
I found some broken vacuum lines going to what I think is the check valve.
 

2BADSTANGS

Member
Jun 19, 2008
385
1
18
Colorado
Jul 31, 2008
#7
  • Jul 31, 2008
  • #7
Sounds like a step in the right direction, The vaccum check valves have two vac lines connected to them and 1 electrical connection there usually black and about 3in tall. Let us know if you get it fixed and what the problem was!
 
J

Jimmy2Times

Member
Jun 9, 2003
63
0
6
Atlanta, GA
Aug 10, 2008
#8
  • Aug 10, 2008
  • #8
GT40 2, did you find the problem? If so what/where was it? I'm having the same problem and so far have not been able to isolate the vacuum leak other than to verify that it's somewhere behind the dash, not under the hood.
 

GT40 2

Member
Oct 13, 2004
109
0
17
Aug 10, 2008
#9
  • Aug 10, 2008
  • #9
I replaced the vacuum thing on the right strut tower today, but it didnt fix anything.
 

2BADSTANGS

Member
Jun 19, 2008
385
1
18
Colorado
Aug 11, 2008
#10
  • Aug 11, 2008
  • #10
Does this problem only occour during acceleration, or if you let the car idle and warm up without accelerating will it still happen?
 

GT40 2

Member
Oct 13, 2004
109
0
17
Aug 11, 2008
#11
  • Aug 11, 2008
  • #11
It only happens during acceleration.
 

glowstang93

20+ Year Stangneter
Feb 9, 2003
853
8
39
Illinois
Aug 11, 2008
#12
  • Aug 11, 2008
  • #12
That thing you replaced on the right strut tower is the EVR or Egr control valve, the computer tells it when to open or not. Of course it is upside down in the pic, lol.

 

GT40 2

Member
Oct 13, 2004
109
0
17
Aug 11, 2008
#13
  • Aug 11, 2008
  • #13
My EVR looks different from that one. What does the check valve look like?
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,169
17,864
224
Massachusetts
Aug 11, 2008
#14
  • Aug 11, 2008
  • #14
Is the A/C on when this happens?
 

GT40 2

Member
Oct 13, 2004
109
0
17
Aug 11, 2008
#15
  • Aug 11, 2008
  • #15
Mustang5L5 said:
Is the A/C on when this happens?
Click to expand...


It doesnt matter, A/C on or off.
 

2BADSTANGS

Member
Jun 19, 2008
385
1
18
Colorado
Aug 14, 2008
#16
  • Aug 14, 2008
  • #16
Check out #58 on this page, I know this is a 5.o, but yours should be in relatively the same place. CJ Pony Parts - Ford Mustang Parts
 

GT40 2

Member
Oct 13, 2004
109
0
17
Aug 14, 2008
#17
  • Aug 14, 2008
  • #17
Mine has a vacuum thing there too.
 

GT40 2

Member
Oct 13, 2004
109
0
17
Aug 14, 2008
#18
  • Aug 14, 2008
  • #18
So I replaced it with another one I got from the junkyard, and it didnt fix anything.
 

GT40 2

Member
Oct 13, 2004
109
0
17
Aug 14, 2008
#19
  • Aug 14, 2008
  • #19
3. Vacuum Storage Canister - Stores Vacuum to prevent interruption of services during wide open throttle

Could that be the problem?
 

2BADSTANGS

Member
Jun 19, 2008
385
1
18
Colorado
Aug 15, 2008
#20
  • Aug 15, 2008
  • #20
It is definately possible. Have you checked the system for leaks? Sounds dumb, but you could pull vacuum lines and suck on them until you find one that dosen't hold pressure well, then inspect it. (If you dont want to anty up the cash for a real tester.) I think the vacuum canister is in the pass. fender. (Don't quote me on that though.) Also try the "stupid" test on the vacuum line going through the firewall near where the heater core hoses connect, because thats the one that provides vacuum to the vent selectors. If it's good, chances are youre problems elsewhere. Let us know what you find, 'cause this could happen to us someday.
 
  • 1
  • 2
Next
1 of 2 Next Last
You must log in or register to reply here.

Similar threads

7
A/C blowing defrost
  • 70/04mach1
  • Jul 20, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
4
Views
266
1996 - 2004 SN95 Mustang -General/Talk- Jul 21, 2025
Noobz347
Electrical need help with a part number
  • alutwon
  • Jan 27, 2026
  • Fox 5.0 Mustang Tech
Replies
0
Views
126
Fox 5.0 Mustang Tech Jan 27, 2026
alutwon
Engine on3 Conversion to draw through MAF?
  • sav22rem22
  • Oct 11, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
249
Fox 5.0 Mustang Tech Oct 11, 2025
sav22rem22
9
1998 V6 - What is this line called?
  • 98_Stanger
  • Aug 10, 2025
  • SN95 V6 Mustang Tech
Replies
5
Views
244
SN95 V6 Mustang Tech Aug 10, 2025
nickyb
B
2001 v6 New compressor issue
  • badmech
  • Apr 30, 2026
  • SN95 V6 Mustang Tech
Replies
0
Views
69
SN95 V6 Mustang Tech Apr 30, 2026
badmech
B
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2.3L (N/A & Turbo) 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?