• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

opinion on engine mods

  • Thread starter Thread starter Kagan
  • Start date Start date Jul 10, 2007
Prev
  • 1
  • 2
  • 3
First Prev 3 of 3

jlangholzj

Mustang Master
Oct 23, 2006
248
31
93
MI
Jul 14, 2007
#41
  • Jul 14, 2007
  • #41
yes and no, although it help when you punch it, it also add gas all the time you apply pedal. my idle is set around 850 and that's why i thought the short lived rev to 1500 was a sign of a rich mixture. what i was talking about was a slow steady acceleration.
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 14, 2007
#42
  • Jul 14, 2007
  • #42
If you didn't throughly clean all the tiny passages in the metering block and throttle body, your problem may be a blocked passage. I learned this the hard way in rebuilding Holleys. I always make damn sure all these passages are free and clear before reassembly. Blow them out with compressed air and then with spray carb cleaner (wear glasses for this) and observe that all are clear. If you've got a list 1850 or 80457 600 cfm carb, the 6.5 PV and 66 jets sound correct. Also check that the check valve is present under the accellerator pump nozzles, if it's not it could pull extra fuel thru that circuit under high vacuum conditions.
 

jlangholzj

Mustang Master
Oct 23, 2006
248
31
93
MI
Jul 15, 2007
#43
  • Jul 15, 2007
  • #43
like i said, i pulled it appart untill i was left with just the body. however i failed to mention that it DOES NOT happen at higher speeds, only from a stop or a very slow crawl. before and after the little blip, it just purrs.

check valve...give me an idea about what i'm looking for plz.

keep in mind that this is on a stock 289 other than a performer in take, ratio411 i already know your oppinion on this
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 15, 2007
#44
  • Jul 15, 2007
  • #44
Remove the squiter nozzle in the throttle body and look down in the screw hole. There should be a solid metal pin about the same diameter as the hole under the screw. It's about 1/8" diameter and 3/8" long. It's pointed at the bottom end. When the pump shoots fuel, it raises this check valve pin. rod, (whatever you want to call it) up to let the fuel stream pass.
 

jlangholzj

Mustang Master
Oct 23, 2006
248
31
93
MI
Jul 15, 2007
#45
  • Jul 15, 2007
  • #45
makes sense, i'll look tonight to make sure. but assuming its in there, im guessing i need a smaller squirter size?
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 15, 2007
#46
  • Jul 15, 2007
  • #46
If you were not aware of that check valve, chances are it ain't there now. It would have likely fallen out of the hole in handling the T/ body while cleaning.
 

ratio411

Founding Member
Apr 21, 2002
3,870
73
109
Pensacola FL
Jul 15, 2007
#47
  • Jul 15, 2007
  • #47
jlangholzj said:
makes sense, i'll look tonight to make sure. but assuming its in there, im guessing i need a smaller squirter size?
Click to expand...

It's very hard to diagnose a carb over the net...

On the squirter:
25 is a very good mild squirter.
I would not focus on it, that is one of the smallest squirters anyway.

If you are still focused on the accel circuit:
Look at the cam. What cam is it?
What linkage location is it in?
What cam hole is the screw located in?
Do you have an umbrella or BB pump valve?
Did you reinstall the restrictor below the squirter?
What model carb are you working on?
What gear ratio do you have?

To do this right, we need LOTS of info.
 
K

Kagan

New Member
May 13, 2006
30
0
0
Turkey
Jul 15, 2007
#48
  • Jul 15, 2007
  • #48
another question came to my mind today. It is not relevant to the new parts. I want to ask you about the vacuum secondaries. If I am not wrong my autolite 4300 has the vacuum secondary option. It means that the 2 barrels work with the vacuum right? But how does it work? Or how can I know if they really open up at the right time??

My car has a spacer too. There is a hole on the spacer by the way. What should be the correct way of attaching everything there between the manifold, carb and this spacer?? Is there a plot or a schematic diagram available? I want to make sure my mechanic connected them right.

If it's important, I have an electronic distributor too. (Proform Street/Strip HEI Distributor)
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 15, 2007
#49
  • Jul 15, 2007
  • #49
The carb spacer either has the PCV hose plugged into it or the EGR system cast into the spacer.
 
K

Kagan

New Member
May 13, 2006
30
0
0
Turkey
Jul 16, 2007
#50
  • Jul 16, 2007
  • #50
but how do I connect all those? If someone could tell it step by step it would be great. I have been looking for info about the carb but couldnt find anything useful.
 
Prev
  • 1
  • 2
  • 3
First Prev 3 of 3
You must log in or register to reply here.

Similar threads

N
Need stainless carb heat shield
  • newmex999
  • Aug 29, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
1
Views
66
1965 - 1973 Classic Mustangs -General/Talk- Aug 30, 2026
Blackhawkxx
Weber Carburetor tuning help
  • SchwarzStock
  • Jul 6, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
4
Views
143
1965 - 1973 Classic Mustangs -General/Talk- Jul 19, 2026
SchwarzStock
N
Edelbrock 1405 Setup
  • nathantaylor200
  • Nov 4, 2025
  • Classic Mustang Specific Tech
Replies
3
Views
284
Classic Mustang Specific Tech Nov 5, 2025
nathantaylor200
N
R
What's it Worth? 1997 Cobra, a ton of mods and restoration
  • riored97snake
  • Jun 18, 2026
  • What is it Worth?!?!?
Replies
2
Views
278
What is it Worth?!?!? Jun 21, 2026
riored97snake
R
9
Engine Donor '00 Mountaineer meet '91 Fox
  • 91firecracker
  • May 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
41
Views
1K
Fox 5.0 Mustang Tech May 28, 2026
91firecracker
9
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang 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?