• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech

Will not having a bigger fuel pump have negative effects on my stang?

  • Thread starter Thread starter CManT1914
  • Start date Start date Aug 23, 2005

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Aug 23, 2005
#1
  • Aug 23, 2005
  • #1
TFS h/c/i combo + stock fuel pump = bad idea?

I never did get around to putting in a bigger fuel pump yet. I was about to order one when I wondered if having the stock fuel pump on would cause any problems. I'll probably order one tomorrow anyway, I was just wondering.
 

tomustang

Psychotic Member
Founding Member
Jun 8, 2000
3,434
2
78
McLean Hospital
Aug 23, 2005
#2
  • Aug 23, 2005
  • #2
if your running too much hp for the stock pump you won't have enough fuel to power the engine.
 

Pokageek

Active Member
Jun 10, 2005
2,767
0
46
MA, USA
Aug 23, 2005
#3
  • Aug 23, 2005
  • #3
I am going to guess "pinging" that you CAN'T hear could be the dangerous aspect of that. How dangerous..don't know.
 

Labora

Founding Member
Jun 11, 2000
1,854
26
69
Dallas, Texas
Aug 23, 2005
#4
  • Aug 23, 2005
  • #4
Just depends. If you are running lean could be very bad. I would hope after you did your HCI you have been checking the plugs to make sure they are colored right and you aren't running too rich/lean?
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Aug 23, 2005
#5
  • Aug 23, 2005
  • #5
Don't strain the brain!

Just put the 255lph pump in the tank and be done with it.

Later
Grady
 

BlackVert

15 Year Member
Oct 3, 2003
5,589
9
98
Bethesda, MD
Aug 23, 2005
#6
  • Aug 23, 2005
  • #6
your combo could use a 255 lph pump and 24# or 30# injectors. why take a chance on not being able to get enough fuel to the engine when you step on it? i'm sure you already know how bad running lean can be for it ...

just my $.02
 

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Aug 23, 2005
#7
  • Aug 23, 2005
  • #7
Well actually I'm having the opposite problem, I'm running to rich. I already have 30lb injectors in there, and my plugs are definitely fouled out from gasoline, so I'm not running lean. Just wondering if there were any other side effects. But I'll order a fuel pump tomorrow anyway.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Aug 24, 2005
#8
  • Aug 24, 2005
  • #8
Good call Chris. The richness you see now is from a lack of tune (my guess). But at WOT, you might end up being lean.

I find that it is very hard to read EFI plugs - even when done correctly after a blast. The EFI just trims fuel too well and runs too lean in general (not like reading carbed plugs).

Good luck Chris.
 

Venom351R

Founding Member
Apr 27, 2002
4,548
41
98
MAINE
Aug 24, 2005
#9
  • Aug 24, 2005
  • #9
Grady speaks the truth.
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Aug 24, 2005
#10
  • Aug 24, 2005
  • #10
HISSIN50 said:
Good call Chris. The richness you see now is from a lack of tune (my guess). But at WOT, you might end up being lean.

I find that it is very hard to read EFI plugs - even when done correctly after a blast. The EFI just trims fuel too well and runs too lean in general (not like reading carbed plugs).

Good luck Chris.
Click to expand...

JT

Been watchin some of your replies and from the looks of em......................

Me thinks your frustration is gonna cause you to come over to the self tuning camp in the near future

Later
Grady
 

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Aug 24, 2005
#11
  • Aug 24, 2005
  • #11
final5-0 said:
JT

Been watchin some of your replies and from the looks of em......................

Me thinks your frustration is gonna cause you to come over to the self tuning camp in the near future

Later
Grady
Click to expand...

Yea if he finds a twEECer for the right price, I think he might succumb to the bug.
 

94MustangGT5.0

New Member
Apr 30, 2003
288
0
0
Champaign, Illinois
Aug 24, 2005
#12
  • Aug 24, 2005
  • #12
I may be wrong, but just because you are running rich does not mean you have adequate fuel pressure. The bigger injectors can be fed fuel through the stock pump, but they won't have enough pressure to do the job that a bigger pump would.
 

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Aug 24, 2005
#13
  • Aug 24, 2005
  • #13
Well I'm looking at fuel pumps right now. I can get a Holley 255lph for $125, a Holley 190lph for $118, a BBK 255lph $122, or a BBK 190lph for $112. Any thoughts on what's better?
 

Grn92LX

Fidanza Man!
Founding Member
Jan 14, 2001
6,819
64
129
New York
Aug 24, 2005
#14
  • Aug 24, 2005
  • #14
I paid $107 shipped for my 255 high pressure pump. Its a walbro, just like all the other ones you mentioned except the manufacturers put their name on the box.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Aug 24, 2005
#15
  • Aug 24, 2005
  • #15
Mike is right on - the BBK will probably have Walbro stamped on the side of it.

That is what I meant before - the 255 is a couple bucks more - might as well go bigger since there is no real downfall from doing so (that I know of).

Grady and Chris, you are both right on. I have been pestering Chris for info on simple things about the TwEECers so I have a little better idea of how all this stuff works. With my luck I would get one and it would do a wicked-witch on me and melt (I hope those things can take interior temps of 180*F+). But yeah, I think one would be cool. Chris is spot on - I would need donations for that one. Perhaps they could just be made to the 'new wheels fund' that I think Greg started on my POS wheel spacer thread.
 

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Aug 24, 2005
#16
  • Aug 24, 2005
  • #16
Hey all right, I found walbro's on eBay. I'm looking at the 255, I can get it for $103 shipped, and it's close too.

JT, somebody started a donation fund for new wheels?
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Aug 24, 2005
#17
  • Aug 24, 2005
  • #17
CManT1914 said:
JT, somebody started a donation fund for new wheels?
Click to expand...
I wish!

On my wheel-spacer thread, one suggested-way to deal with the issues I have was to get new wheels. I wish! As I said on there, if I did that, I would be running around with nice wheels and 315's out back, like my buddy Chris.
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Aug 24, 2005
#18
  • Aug 24, 2005
  • #18
94MustangGT5.0 said:
I may be wrong,
Click to expand...

No your not

but just because you are running rich does not mean you have adequate fuel pressure. The bigger injectors can be fed fuel through the stock pump, but they won't have enough pressure to do the job that a bigger pump would.
Click to expand...

Looks good to me

Later
Grady
 

94TURBO5 O

New Member
Mar 14, 2004
2,509
0
0
VA
Aug 24, 2005
#19
  • Aug 24, 2005
  • #19
final5-0 said:
Don't strain the brain!

Just put the 255lph pump in the tank and be done with it.

Later
Grady
Click to expand...
Yup I ran just fine with a 255 intank only with all my past combos.
I just recently added an inline for the turbo set-up.
 
You must log in or register to reply here.

Similar threads

B
Electrical Why does my fox body keep frying eecs
  • brandyn200
  • Jun 20, 2026
  • Fox 5.0 Mustang Tech
Replies
8
Views
270
Fox 5.0 Mustang Tech Jun 25, 2026
AeroCoupe
Fox Xtremely high fuel consumption
  • PonyGTrider
  • Apr 11, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 9 10 11
Replies
213
Views
4K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 9, 2026
PonyGTrider
1999 Mustang GT - No Start- Need help understanding the fuel pump circuit and how it works
  • 99gtGuy
  • Nov 4, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
531
1996 - 2004 SN95 Mustang -General/Talk- Nov 7, 2025
04newedge-
0
B
'03 GT Fuel Pump/Pressure/Delivery Issue
  • Brodach
  • Oct 21, 2025
  • SN95 4.6L Mustang Tech
Replies
8
Views
918
SN95 4.6L Mustang Tech Oct 31, 2025
gkomo
Resolved 93 Mustang 5.0 - Cranks but does not start
  • dan50
  • Jul 18, 2026
  • Fox 5.0 Mustang Tech
Replies
6
Views
141
Fox 5.0 Mustang Tech Jul 18, 2026
dan50
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific 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?