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

I've got boost!!

  • Thread starter Thread starter Acid7711
  • Start date Start date Aug 10, 2006
  • 1
  • 2
Next
1 of 2 Next Last
A

Acid7711

Member
Sep 4, 2005
41
0
6
TN
Aug 10, 2006
#1
  • Aug 10, 2006
  • #1
Well, one of my life goals has been complete! I've supercharged my car. I went with the Kenne Bell kit, I believe they upgraded it to the 2.2? I think so.

Anyways, install went smooth, runs great, no detonation, but I'm having a slight problem. I went with the Boost-a-pump route because that's what KB recommened saying in tanks will mess with idle fuel pressure as well as heat the fuel excessivly.

Problem is, with the BAP turned off, under wot at 2k rpms, fuel pressure is perfect, 65-70psi. Runs great, pulls hard, very nice. However, at about 4k rpms my fuel pressure starts to drop, maybe around like 55psi. This is the problem I'm having, I'm not understanding why it's dropping.

I decided to use the BAP and turn it up, and when I do, I get my fuel pressure perfect at 4k rpms under wot, a steady 65-70psi. However, when I go wot at 2k rpms, because of the BAP, it shoots my fuel pressure up to 80psi. This is wayyyyyy to high. I can tell the car is just running rich.

I emailed KB, but they are slow to respond. Not their fault, I'm sure they get hundreds of emails a day. What can I do to fix this problem? Either way, I'm not getting any detonation, but I'm thinking that 55psi wot at 4krpms isn't good. I haven't brought it any higher than that, so I don't know what happens after that.

Thanks in advance.
 

68torinogt

Hey guys, guess what--I have a bi-pass!!!
Mar 21, 2006
0
0
53
Welcome my son, welcome to the machine
Aug 10, 2006
#2
  • Aug 10, 2006
  • #2
have it tuned??
 
M

Marlboro_Man

Member
Sep 30, 2005
437
1
18
Houston, TX
Aug 10, 2006
#3
  • Aug 10, 2006
  • #3
Wheres Dagger?
 

bynummustang

Seen my other Jackstand?
Jul 24, 2005
1
2
69
NC State University
Aug 10, 2006
#4
  • Aug 10, 2006
  • #4
Ask daggar, or get a custom chip burnt.

Oh, can you get a vid of it, I've always loved KB.
 

2000xp8

SN Certified Technician
Aug 8, 2003
8,015
1,612
194
NJ
Aug 10, 2006
#5
  • Aug 10, 2006
  • #5
What injectors are you running?
Sounds like stock ones, from your description. And that's not a good thing.
Also, a 255 in tank, would of likely been plenty good.
 
A

Acid7711

Member
Sep 4, 2005
41
0
6
TN
Aug 10, 2006
#6
  • Aug 10, 2006
  • #6
Yeah, I've been waiting for my twEECer r/t for 2 weeks now. Company I ordered from claims they're backordered for like a month now. This is great hah.

I was thinking about getting a 255 high pressure pump for the FI that I've done, however wouldn't putting a larger fuel pump in increase the pressure of the system throughout the entire rpm range including idle? I thought I had a good grasp on all of this, but conflicting info from 100's of searches by myself and reading all sorts of other information has my head spinning. I'm still seeing the stock pump with the boostapump being like 137 or so. I think that should support 5-6 psi just fine, especially since when I crank it up, it runs really rich.



I am using the stocker injectors, but I don't see injectors causing a pressure drop though. I talked to KB for a while on the phone and they assured me that for the basic kit they'd be more than enough with a boost-a-pump, they even told me I didn't need the boost-a-pump, however I wanted to get it to be safe. Gah.

I know who Daggar is, but only from seeing the name on here. Nothing beyond that. Thing is, I don't have a tuning shop anywhere near here. I'd probably have to drive like at least 3-4 hours. At LEAST.
 

795.0pacecar

lover of pudgy polygamists
Jul 11, 2003
480
0
17
Senoia, GA
Aug 11, 2006
#7
  • Aug 11, 2006
  • #7
The 255 pump wont add pressure, it will add volume.
 
D

dwhiskie

New Member
Sep 18, 2004
183
0
0
Aug 11, 2006
#8
  • Aug 11, 2006
  • #8
If your using stock inj. Better keep the wallet near by.
 

2000xp8

SN Certified Technician
Aug 8, 2003
8,015
1,612
194
NJ
Aug 11, 2006
#9
  • Aug 11, 2006
  • #9
dwhiskie said:
If your using stock inj. Better keep the wallet near by.
Click to expand...
And a spare set of Head gaskets.

Get a pro m meter and injectors. Cancel your order on the tweecer, you really don't need it at the moment.
From your description of what you are doing, and how you are doing it, a tweecer is above your level at the moment, and will likely make your car worse, not better.
No insult intended, we all learned somewhere.
 

89Notch

Founding Member
Oct 21, 1999
1,669
0
0
MSU
Aug 11, 2006
#10
  • Aug 11, 2006
  • #10
fuel pressure regulator
 
A

Acid7711

Member
Sep 4, 2005
41
0
6
TN
Aug 11, 2006
#11
  • Aug 11, 2006
  • #11
Cancel my order for the tweecer and get injectors/maf and a pump is what your saying. So I wasted my money on the boostapump 1st, 2ed getting those meters that I've read sooooo much controversy over is a "good" idea. All that tricking the computer stuff. Don't they just advance the timing and such to fool the computer? Isn't that a bad thing?

What fuel pump, a 255 high pressure or just a regular one? What size injectors then?


All that and the car will run fine huh? No twiddling or tuning needed? Seems a little too good to be true, but what do I know all of this 'is above my level.' For everyone's info, I canceled my order for the tweecer. I really hope that in fact, I didn't really need it.......

I still don't understand why the boostapump isn't going to work for me. I'm pretty pissed about drilling 2 holes in my dash for something that's going to do me no good now, muchless wasting $200 on it.

I'm not planning to ever up the boost. 5-6 psi is fine for me. I take it with this fuel pump, injectors, and maf I'll still be using the fmu? And if not I'm still going to somehow get it to be drivable for like a 4 hour drive while I attempt to find someone that can tune it since I live in the middle of no where.

Hopefully someone has some answers. I hate hearing I'm a stupid newb who just wasted his money.
 

Jaswir

Member
Mar 31, 2005
578
0
18
Orlando, FL
Aug 11, 2006
#12
  • Aug 11, 2006
  • #12
buy adding a 255lph fuel pump will by no means add more pressure, because thats what the return line is for...
 
A

Acid7711

Member
Sep 4, 2005
41
0
6
TN
Aug 11, 2006
#13
  • Aug 11, 2006
  • #13
Ok, case closed on that. Now what size injectors so I can get one of these maf's that are 'calibrated' for the injectors. 24's gonna be enough? I have a friend that was going to sell me his 30's, but these mafs are hard to find in 30's,
 

2000xp8

SN Certified Technician
Aug 8, 2003
8,015
1,612
194
NJ
Aug 11, 2006
#14
  • Aug 11, 2006
  • #14
I really didn't hear anyone say "stupid newb wasted his money".

Very few people get their setup right the first time, myself included. It's a learning experience, especially when you have to do all the work yourself.

I've never believed in the aftermarket tuner for a foxbody. It can help when you have a pretty wild combo, but for the mild stuff, i just don't see the point. People have been getting these cars to run just fine without them, for the last 17 years.

I don't know for sure how much power a KB makes with that amount of boost, but i'm sure it's into the 24lb injector zone, at least. Thus you need a new meter to go with them. Then as said above, you'll need an adjustable fuel pressure regulator.
I've seen guys use the 255 lph in tank, for 485rwhp, so i'm sure it can handle your car. Simple and easy.

PMAS, has any maf you want, for any calibration. I suggest using the 80mm, seems to be the most accurate.
 
A

Acid7711

Member
Sep 4, 2005
41
0
6
TN
Aug 11, 2006
#15
  • Aug 11, 2006
  • #15
Alright. Hopefully they get my message in time and cancel my order.

You think I'm going to need larger than 24's?

So far I need to get:
-255 fuel pump
-adjustable fpr
-at least 24lb injectors
-pro m maf calibrated for said injectors


One thing I'm not understanding is with this setup, what is compensating for the additional air being forced into the engine fuel wise? Will doing this get rid of the fmu, or will I still retain it? I can see that the pump gives it enough fuel, the injectors will flow more, but won't the ECU be trimming the injectors? Under boost does it know to add more fuel?


I had a goal to get everything up and running decently before the 18th of this month, doesn't look like it's gonna happen. Was having a big meet with a lot of people I haven't seen in many years.
 

2000xp8

SN Certified Technician
Aug 8, 2003
8,015
1,612
194
NJ
Aug 11, 2006
#16
  • Aug 11, 2006
  • #16
Realistically, with that list of mods you have to do, it's like 2 hours of work, no biggie.

These guys will direct you better with the FMU, than i will.
When you get the car done, and running fine, then if you want to tweak it with the tweecer go ahead.
 
A

Acid7711

Member
Sep 4, 2005
41
0
6
TN
Aug 11, 2006
#17
  • Aug 11, 2006
  • #17
If I can get it running good without the tweecer, great. I'm not worried about the amount of time involved on putting it on. I'm pretty mechanically inclinded, I'm worried about the time it takes to ship stuff, and how long it'll take me to figure out what I need to do to get it to work.
 
9

90bluegt

Founding Member
Dec 9, 1999
592
0
16
Aug 11, 2006
#18
  • Aug 11, 2006
  • #18
How much horse are you running or projecting to run? If you around 400 horse you'll need 30#ers. If more then i would look at getting 36#ers.

Thanks
A very nice link:
http://www.megamanual.com/v22manual/minj.htm
 
A

Acid7711

Member
Sep 4, 2005
41
0
6
TN
Aug 11, 2006
#19
  • Aug 11, 2006
  • #19
I figure I'm about like 300ish hp right now. I figure this is about my max, maybe 350. That's probably about my goal. All I've wanted to do with this car is just break into 12's.
 

tunedin302

I AM the law!!!
Jul 29, 2004
1,251
2
36
Pennsylvania
Aug 11, 2006
#20
  • Aug 11, 2006
  • #20
I run a blower and have great luck with the following:
1. Walbro 255lph forced induction pump (High Pressure Pump: ends in 340) - good to 550hp
2. Adjustable FPR
3. 30lb FMS injectors
4. Pro-M 80mm mass air calibrated for s/c and 30lb injectors

If you keep the FMU (run an injector less than 42lb) then you will have to change the disc in the FMU at the time you change the injectors. Good luck.
 
  • 1
  • 2
Next
1 of 2 Next Last
You must log in or register to reply here.

Similar threads

K
Engine 2000 Mustang GT - Fuel issue post-blown spark plug repair
  • kenster1092
  • Feb 26, 2026
  • SN95 4.6L Mustang Tech
Replies
4
Views
283
SN95 4.6L Mustang Tech Mar 10, 2026
kenster1092
K
S
Engine I am having trouble with the engine in my 1991 Mustang.
  • sands9330014
  • Sep 28, 2024
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
47
Views
1K
Fox 5.0 Mustang Tech Apr 12, 2025
Mindseye007
S
Fuel ‘88 GT Runs Rich Cold — Fixes Itself When I Unplug Sensors (ECT, MAF, O2, etc.)
  • Sufarry
  • Nov 6, 2025
  • Fox 5.0 Mustang Tech
Replies
12
Views
706
Fox 5.0 Mustang Tech Nov 9, 2025
Mustang5L5
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
F
Trouble Shooting Sudden Shift of AFR at low RPM
  • Farva_84
  • Jun 6, 2025
  • SN95 4.6L Mustang Tech
Replies
8
Views
430
SN95 4.6L Mustang Tech Jun 8, 2025
Farva_84
F
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?