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

Autolite 4100

  • Thread starter Thread starter notny41
  • Start date Start date Sep 14, 2004
Prev
  • 1
  • 2
  • 3
First Prev 3 of 3

notny41

Member
Aug 15, 2004
204
0
16
Minnesota
Sep 25, 2004
#41
  • Sep 25, 2004
  • #41
Right now I'd just settle for an engine that runs smooth once it is warmed up! The dang thing seems to act like it is flooding or starving or like the plugs are fouling whenever you try to hold the engine speed at a constant rpm. Then when you press the pedal down it jumps back to life again. The plugs all look like they should.

I'll tell you too that when I first started it tonight, it required about a 1/16th of an inch opening or less for the choke to keep the car running and that was when I used my finger to get the butterfly to stay at that position. And it was such a precision opening that I doubt the carb could ever be adjusted that accurately to maintain the engine. There is just too much play in all of the linkage...

So, I'm giving up on the hopes that I'll ever have an engine that you could pump once and turn the key and the thing would just warm up on its own and adjust idle speed accordingly without the need for pumping the pedal.

Like I said before, I'd just be satisfied if I could get in and drive it without the sensation of "running out of gas" whenever I try to keep a constant speed. I reset the idle mixtures back to 1 3/4 turns out from fully seated and that seemed to help when the engine was cold but not once the thing warmed up.

And I don't know if it could be that the coil is going faulty once it warms up but it didn't feel that warm on the outside of it after I turned the engine off.



I am just getting so frustrated!!!

I used to have a 67 t-5 with a 289 in it and that thing ran like a sewing machine. I don't understand why this one is being so damn finicky.

What's your best guess on my "out-of-gas" sensation that I am getting: Fuel-Delivery or Ignition related? And what's the best (least expensive) test for either?
 
6

65Mustang2+2

New Member
Jun 5, 2004
118
0
0
Connecticut
Sep 25, 2004
#42
  • Sep 25, 2004
  • #42
Paul,
Is that a rebuilt Pony Carb? If it is send it back them, let them do all the fuel mixtures settings for you! All you need to do is adjust the choke when you get it back from them!
 
J

JB66

New Member
Aug 21, 2004
565
1
0
New York
Sep 25, 2004
#43
  • Sep 25, 2004
  • #43
So, you didn't have to keep pumping it to keep it running? If not, you're gaining! The air flow through the carb will tend to pull the butterfly open also. Before you go any further with the choke, you need to get it running properly fully warmed up. The choke can't be used to compensate for other problems. Has the carb been rebuilt? There may be an internal passage or more likely a jet that is restricted. I might also think the float level might be too low on the primary side and when you open up the throttle the sondaries start to kick in and supply the needed fuel. Don't give up!
 

notny41

Member
Aug 15, 2004
204
0
16
Minnesota
Sep 25, 2004
#44
  • Sep 25, 2004
  • #44
My appologies to JB66 as he was the first one (and early on in the thread) to suggest that it sounds like I have a vaccuum leak.

Don't know why I waited this long to try the most simple of tests (probably because I wasn't sure what was supposed to happen), but I sprayed carb cleaner near the base of the carb spacer and the engine shot up in RPM's. Sprayed it on the other side of the carb in the same spot and nothing happened.

I pulled off the carb and the spacer and it is very apparent that the person that converted this from two barrel to 4 put the wrong gaskets on. I called Autozone and they have the proper gaskets on hand for 99 cents each. I haven't had a chance to sneak up and get them yet but I'm betting that when I put the correct ones on I will have some problems solved and then I can adjust the choke and the idle mix screws properly...

I'll let you know what happens after I put the right gaskets on.
 

notny41

Member
Aug 15, 2004
204
0
16
Minnesota
Sep 25, 2004
#45
  • Sep 25, 2004
  • #45
Put the new (and correct) gaskets on and you'd never know how much difference $1.98 could make.

I am a happy camper. Purring like a kitten and cold starts like a dream. No more pumping the gas pedal after turning the key!!!

Vaccuum leaks suck!

Me =

Thanks to everyone for the helpful posts - especially JB66, Ozsum2, and 302 Coupe! Everyone else, gets honorable mention! Thanks again!

P
 
G

GeeTeeStanggirl

New Member
Apr 13, 2004
3
0
0
North Hills CA.
May 28, 2008
#46
  • May 28, 2008
  • #46
Another 4100 Carb Question- Need Pictures

I have a 4bbl 4100 on my stang. I need to view pictures of the springs hookups to the back of the intake and to the throttle link ( I think I stating them right) My enginge revs high and not always I can kick it down. I found out that my throttle cable needed replacing, and it was but they adjusted my springs, moved them. This because the car has an increasing rev. Sometime with my foot on the pedal it will go as fast as 40mph. So when I got home, I myself replaced the accelator pump gasket ( in front of the carb- - gas linking) and now it is fixed no leaks but when i step on the gas the spring flew off. Thank god i was home and not driving. Therefore i need images of the carb hook ups etc. Any one got pictuces?
 
R

runawayabc123

Member
Mar 9, 2007
192
0
16
Wisconsin
May 28, 2008
#47
  • May 28, 2008
  • #47
Try this site for pictues, lots of 4100 to choose from if some of the pics don't work.

http://www.mustangtek.com/4100/ford4100.html
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
May 28, 2008
#48
  • May 28, 2008
  • #48
After reading all this I'm thinking now.......................for such a simple carb, there sure is a lot of monkeying around to get it to run right. I'll stick with Holleys. One thing that I will add to the mix here is are y'all still running points with this 4100? If you are, that's half your problem. If you got em, they need to be replaced with an electronic module..
 
B

bnickel

Founding Member
Aug 21, 2002
5,640
3
77
lubbock, texas
May 28, 2008
#49
  • May 28, 2008
  • #49
GeeTeeStanggirl said:
I have a 4bbl 4100 on my stang. I need to view pictures of the springs hookups to the back of the intake and to the throttle link ( I think I stating them right) My enginge revs high and not always I can kick it down. I found out that my throttle cable needed replacing, and it was but they adjusted my springs, moved them. This because the car has an increasing rev. Sometime with my foot on the pedal it will go as fast as 40mph. So when I got home, I myself replaced the accelator pump gasket ( in front of the carb- - gas linking) and now it is fixed no leaks but when i step on the gas the spring flew off. Thank god i was home and not driving. Therefore i need images of the carb hook ups etc. Any one got pictuces?
Click to expand...



if you buy a carb kit (i like borg warner or motorcraft) they will usually have all the info for which rods go in which holes, etc for your model number carb, which will be on the base of the carb on the left front mounting ear. once you have the model number you can go down the list to see which holes apply to your carb.
 
B

bnickel

Founding Member
Aug 21, 2002
5,640
3
77
lubbock, texas
May 28, 2008
#50
  • May 28, 2008
  • #50
D.Hearne said:
After reading all this I'm thinking now.......................for such a simple carb, there sure is a lot of monkeying around to get it to run right. I'll stick with Holleys. One thing that I will add to the mix here is are y'all still running points with this 4100? If you are, that's half your problem. If you got em, they need to be replaced with an electronic module..
Click to expand...


D, take a look at my post above, it's really not any different than setting a holley when you take into account all the settings you have to do on a holley like accellerator pump, etc just one a holley you do it with screws.
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
May 29, 2008
#51
  • May 29, 2008
  • #51
bnickel said:
D, take a look at my post above, it's really not any different than setting a holley when you take into account all the settings you have to do on a holley like accellerator pump, etc just one a holley you do it with screws.
Click to expand...

Yea, I know, just thought I'd pull their chains. The idle and choke business can be eliminated in some cases with an ignition upgrade from points .
 
B

bnickel

Founding Member
Aug 21, 2002
5,640
3
77
lubbock, texas
May 29, 2008
#52
  • May 29, 2008
  • #52
D.Hearne said:
Yea, I know, just thought I'd pull their chains. The idle and choke business can be eliminated in some cases with an ignition upgrade from points .
Click to expand...



true dat, i should hook up my mallory hy-fire to the stang too, but it's an old one and since i'm going for an "old skool" look on the cougar i may save it...can't decide
 
Prev
  • 1
  • 2
  • 3
First Prev 3 of 3
You must log in or register to reply here.

Similar threads

Help with AFR reading
  • dz01
  • Nov 14, 2024
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
8
Views
503
1965 - 1973 Classic Mustangs -General/Talk- Jan 8, 2025
GOvert
G
Place to Avoid: Jamison Auto Group in Gulfport, MS
  • D Durden
  • Oct 20, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • 2 3
Replies
45
Views
2K
1965 - 1973 Classic Mustangs -General/Talk- Feb 4, 2026
nickyb
K
Engine 2000 Mustang GT - Fuel issue post-blown spark plug repair
  • kenster1092
  • Feb 26, 2026
  • SN95 4.6L Mustang Tech
Replies
4
Views
290
SN95 4.6L Mustang Tech Mar 10, 2026
kenster1092
K
Drivetrain 83’ Glx convertible C5 Trans help!
  • JacksonJared2113
  • Dec 25, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
335
Fox 5.0 Mustang Tech Dec 26, 2025
JacksonJared2113
M
Progress Thread mnky99 2001 V6 evap core, ac compressor, heater core replacement
  • mnky99
  • Sep 5, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
441
1996 - 2004 SN95 Mustang -General/Talk- Sep 5, 2025
mnky99
M
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?