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

Engine Sluggish 302HO

  • Thread starter Thread starter Skrause118
  • Start date Start date Jul 1, 2022
  • Tags Tags
    302 ho carburetor foxbody
S

Skrause118

New Member
Jan 20, 2022
7
0
1
Fort myers, FL
Jul 1, 2022
#1
  • Jul 1, 2022
  • #1
Hello all, I have an 88 Fox mustang GT with 302 roller motor. Has about 180psi of compression in all 8 cylinders. I was sick of the old efi so I carb swapped it. I put an Edelbrock rpm air gap intake, redone E7 heads, stiffer comp cam valve springs, a b303 cam, roller tip 1.6 rockers, and a brand new edelbrock AVS2 650cfm carburetor. also an hei distributor. I haven’t touched it at all. The timing is set at 10 degrees. The car is extremely slow, I’ve been in many foxbodies carb swapped and all, this is by far the slowest. Can anyone help out? This is also my daily driver. Thanks!
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,827
10,508
203
polk county florida
Jul 1, 2022
#2
  • Jul 1, 2022
  • #2
Sorry to hear you carb swapped it, not many around here deal with carbs anymore. There is a lot to tuning with a carb, lets ask some questions first: is there a vacuum canister on the distributor? Is the carb straight out of the box? Do you have a vacuum gauge?
Oh,and what gear in the rear?
 
S

Skrause118

New Member
Jan 20, 2022
7
0
1
Fort myers, FL
Jul 1, 2022
#3
  • Jul 1, 2022
  • #3
General karthief said:
Sorry to hear you carb swapped it, not many around here deal with carbs anymore. There is a lot to tuning with a carb, lets ask some questions first: is there a vacuum canister on the distributor? Is the carb straight out of the box? Do you have a vacuum gauge?
Oh,and what gear in the rear?
Click to expand...
I’m not sure what gear is in the rear. At about 70mph I’m at 2000 rpm. The carb hasn’t been tuned it was just thrown on out of the box. The vacuum advance on the distributor is capped because it was running at 46 degrees total timing and 36 with it capped off just using the springs in the distributor. And I do have a vacuum gauge. I’m just wondering if the jets in the carb are either too big or too small.
 
M

Monkeybutt2000

Mustang Master
Aug 11, 2019
1,387
848
133
Lafayette,IN
Jul 1, 2022
#4
  • Jul 1, 2022
  • #4
I have to ask,why would you take an efi system off for a carb??
 
Reactions: Adieu
S

Skrause118

New Member
Jan 20, 2022
7
0
1
Fort myers, FL
Jul 1, 2022
#5
  • Jul 1, 2022
  • #5
Monkeybutt2000 said:
I have to ask,why would you take an efi system off for a carb??
Click to expand...
The cars wiring harness internal and external were butchered. I didn’t have the money to go buy everything new and do it right so this was my quick solution.
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Jul 1, 2022
#6
  • Jul 1, 2022
  • #6
So your max timing is plenty, but it needs some recurving, and initial timing sounds good at 10 deg. Is that for sure BTDC?.

What type of fuel pump and what pressure are you using?
 
S

Skrause118

New Member
Jan 20, 2022
7
0
1
Fort myers, FL
Jul 1, 2022
#7
  • Jul 1, 2022
  • #7
7991LXnSHO said:
So your max timing is plenty, but it needs some recurving, and initial timing sounds good at 10 deg. Is that for sure BTDC?.

What type of fuel pump and what pressure are you using?
Click to expand...
I am using stock fuel pump, just used adapters and a fuel pressure regulator that’s regulated to 6.5 going to the carb.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,827
10,508
203
polk county florida
Jul 1, 2022
#8
  • Jul 1, 2022
  • #8
What do the plugs look like?
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Jul 1, 2022
#9
  • Jul 1, 2022
  • #9
Skrause118 said:
I am using stock fuel pump, just used adapters and a fuel pressure regulator that’s regulated to 6.5 going to the carb.
Click to expand...
The stock in tank EFI pump? I bet if you check your plugs, the stock pump is too much for the regulator, and is flooding the car. This has not worked out well in the past.
Here is one solution. It’s still overkill for your build, but will work much better.
https://www.summitracing.com/parts/hly-12-802-1?seid=srese2&utm_source=bing&utm_medium=cpc&utm_campaign=Brands+%7C+H&utm_term=4581939832669220&utm_content=GSAPI+5ba272f94185f
At your power level, Airtex makes an external pump that would be sufficient at a lower cost. I’ll check in an old car group and see if I can get back with a number.
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Jul 1, 2022
#10
  • Jul 1, 2022
  • #10
Here is a 5-9 psi and 30 gph external pump that will run a carb. (My other project needs the 4 psi version when under the hood, mechanical ones are waiting for a short production run.)
Airtex mpn194840398

Airtex® E8090 - In-Line Electric Fuel Pump

In-Line Electric Fuel Pump - Part Number E8090 by Airtex. With Hoses, Clamps and Bracket, 2 Connectors, 5/16" Hose. Available in Parts Department at www.carid.com
www.carid.com
 
Last edited: Jul 2, 2022
You must log in or register to reply here.

Similar threads

D
Engine HO cam in non HO roller block ‘93 f150
  • DanC1993f150
  • Mar 21, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
211
Fox 5.0 Mustang Tech Mar 29, 2026
General karthief
6
Hey all,I’m putting together a 302 for my 1968 Mustang and wanted to post the combo + some questions to make sure I’m not missing crucial
  • 68_Disgustang
  • Feb 22, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
3
Views
669
1965 - 1973 Classic Mustangs -General/Talk- Feb 28, 2026
Noobz347
H
Brand New Built 302 overheating
  • hassler
  • Sep 26, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
23
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 26, 2025
Rcdgl
R
new :poo: box, may need to hit you guys up for 79-82 info when i fix thIs turd.
  • rednotch
  • Sep 27, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2 3
Replies
40
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 4, 2026
Noobz347
S
Requesting Guidance for 306 motor swap - Fuel? - SD? MAF?
  • So_Flo
  • Jul 26, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
32
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 4, 2026
Mcmahst
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?