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

Fox HELP PLEASE Surging idle and then Stalls

  • Thread starter Thread starter Luisr010
  • Start date Start date Jun 16, 2023
L

Luisr010

Member
Jun 25, 2022
19
2
13
Miami, FL
Jun 16, 2023
#1
  • Jun 16, 2023
  • #1
need help my mustang is stalling.
It’s a 1987 ttop Mustang GT.
It starts and surges high for a second then low rpm bouncing until it dies.
So far what I’ve done:
Fuel pump, Fuel pump relay, Fuel tank, fuel filter,
Fuel pressure regulator, tfi module, egr valve.

Took off my intake to and inspected all the hoses.
I get 30 psi at the rail at the front.
I spray starter fluid after the maf a little bit and it
Evens out and runs nice. Then it stumbles and stalls again.
I’m all out of idea I need HELP please.
 

mikestang63

SN Certified Technician
Aug 27, 2012
11,606
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In the garage
Jun 16, 2023
#2
  • Jun 16, 2023
  • #2
do the checklist in the sticky
 
L

Luisr010

Member
Jun 25, 2022
19
2
13
Miami, FL
Jun 16, 2023
#3
  • Jun 16, 2023
  • #3
it was running before fine I did go through the checklist but couldn’t find anything wrong
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,236
17,921
224
Massachusetts
Jun 16, 2023
#4
  • Jun 16, 2023
  • #4
30 psi in what condition? Vacuum line off and plugged?

You should have 39-40psi. If only 30 you should investigate why it’s low.

Also, dump codes and perform vacuum leak/smoke test
 
L

Luisr010

Member
Jun 25, 2022
19
2
13
Miami, FL
Jun 16, 2023
#5
  • Jun 16, 2023
  • #5
I performed the smoke test multiple times no leaks either. And it shoots up to 40 psi then lowers to 30 psi this is while the key is in the on position
 
L

Luisr010

Member
Jun 25, 2022
19
2
13
Miami, FL
Jun 16, 2023
#6
  • Jun 16, 2023
  • #6
Mustang5L5 said:
30 psi in what condition? Vacuum line off and plugged?

You should have 39-40psi. If only 30 you should investigate why it’s low.

Also, dump codes and perform vacuum leak/smoke test
Click to expand...
In the ON position I get codes: 81o 82o 95o 81o 10o
With the car on while it surges i get codes: 21r 41r 91r 33r
 
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