• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

fuel pressure regulator

  • Thread starter Thread starter derrick gil
  • Start date Start date Jul 9, 2008

derrick gil

Member
Jun 18, 2007
67
5
9
Jul 9, 2008
#1
  • Jul 9, 2008
  • #1
Hi guys. I recently put a 331 stroker in my 89GT. It has a 75mm. mass air flow, 70mm. throttle body, holley systemax intake, AFR 185 heads, 30# injectors, cold air intake, off road h-pipe, and 3:73 gears. I'm about to put a walbro 255lpf fuel pump and an adjustable fuel pressure regulator. I'm just wondering what I should set the regulator at. I'm going to get it tuned, but I want to break the engine in first. Any thoughts on what pressure I should set the regulator would be very helpful. Thanks
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,811
234
Dublin GA
Jul 9, 2008
#2
  • Jul 9, 2008
  • #2
Get one of your buddies to ride along with you. Find a level stretch of road where you can do some testing. Watch for the wind speed and direction, it can have a definite impact on your test results.

Don't choose a speed range that will make you shift gears, the shift quality & speed will affect your results. Use 2nd or 3rd gear and do a run from 2000 RPM to 5800 RPM. Call out the RPM as it increases and have your buddy record it and the elapsed time. If you have one of those cheap digital watches like I do, a stop watch is built in.

Start the fuel pressure at 36 PSI, vacuum off and make a run. Turn it up to 37 and make another. Be sure to reconnect the vacuum every time you set the pressure. Keep turning up the pressure and making runs until you notice a drop off in time. If your bud was careful to record the results, you'll have a nice chart to use to find the optimum pressure.
 
You must log in or register to reply here.

Similar threads

D
Fuel Erratic Fuel Pressure 1985 GT
  • DienstXIV
  • Jan 14, 2026
  • Fox 5.0 Mustang Tech
Replies
16
Views
631
Fox 5.0 Mustang Tech Jan 16, 2026
AeroCoupe
K
Digital Tuning Going heads/cam/intake. Do I need a tune?
  • karhoot
  • May 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
41
Views
477
Fox 5.0 Mustang Tech May 14, 2026
karhoot
K
1
Engine 91 mustang 302 Low acceleration car backfires pops and acts like it doesn’t want to take fuel
  • 1991Fox5.0
  • Oct 4, 2025
  • Fox 5.0 Mustang Tech
Replies
16
Views
952
Fox 5.0 Mustang Tech Oct 6, 2025
1991Fox5.0
1
9
Forced Induction Prepping for supercharger on non-stock build
  • 91fox427
  • Nov 25, 2025
  • Fox 5.0 Mustang Tech
Replies
7
Views
376
Fox 5.0 Mustang Tech Jan 5, 2026
Qtrhrse23
Q
C
03 Cobra Low Fuel Pressure
  • CTsnake_03
  • Mar 17, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
5
Views
216
1996 - 2004 SN95 Mustang -General/Talk- Mar 24, 2026
CTsnake_03
C
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang 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?