Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

About Holley's

Thread Tools
 
Search this Thread
 
Old Apr 1, 2015 | 10:19 AM
  #1  
F-250 restorer's Avatar
F-250 restorer
Thread Starter
|
Lead Driver
15 Year Member
Photogenic
Liked
Loved
Joined: Mar 2008
Posts: 7,175
Likes: 377
From: Near Los Angeles
About Holley's

I recently installed my first Holley, an 1848, 465 cfm vacuum secondary, with the hot air choke. I'm now learning the Holley.

It is on a pepped up 300 inline with the hp of a 360 with a 2v carb.

I am posting because of an issue that has me stumped. It starts and idles fine, but after driving a bit when I come to a light the idle drops lower and it starts to chug, as if it is going to stall. It has an auto trans. If I shift into N or P it runs smooth, but slower rpm than set. I should mention the carb was NOS, and had set on a shelf for untold years, with paper gaskets. I went through it and put in a kit.

I have had issues with header heat causing fuel boil/vapor lock and am getting ready to change header--which is right under the carb/intake--to efi manifolds. Does this sound like a heat issue? or possibly a foreign body in the idle circuit?
 
Reply
Old Apr 1, 2015 | 07:54 PM
  #2  
orangeford's Avatar
orangeford
Laughing Gas
25 Year Member
Photogenic
Liked
Loved
Joined: Aug 2000
Posts: 1,005
Likes: 63
From: Eastern, Idaho
Hard to say. One thing I found that makes these things easy to figure out is a wide band air/fuel ratio meter. I got one from summit, wired it to a cig lighter plug and use it for diagnosis stuff. It requires installing a port in the exhaust for the o2 sensor. The benefit is knowing if it lean or rich and when instantly. Then you know what to fix.

I would look at float level and vacuum leaks. Holleys tend to have less problems with heat but thats on V8s. I suppose it could be heat related.
 
Reply
Old Apr 1, 2015 | 08:20 PM
  #3  
HIO Silver's Avatar
HIO Silver
Fleet Owner
Joined: Dec 2009
Posts: 20,678
Likes: 82
From: NorCal
I am no Holley aficionado but...


Autolites on automatic trans-equipped vehicles had a deceleration valve which prevented the carb from slamming shut when ya let off the pedal. I think that principle might be amiss on that Holley.
 
Reply
Old Apr 1, 2015 | 08:50 PM
  #4  
rlb652_674's Avatar
rlb652_674
Junior User
Joined: Jun 2009
Posts: 58
Likes: 0
From: West Seattle
Have you adjusted the primary floats? Sounding like they might be a touch high. How did you adjust the mixture?
 
Reply
Old Apr 1, 2015 | 11:48 PM
  #5  
F-250 restorer's Avatar
F-250 restorer
Thread Starter
|
Lead Driver
15 Year Member
Photogenic
Liked
Loved
Joined: Mar 2008
Posts: 7,175
Likes: 377
From: Near Los Angeles
Originally Posted by rlb652_674
Have you adjusted the primary floats? Sounding like they might be a touch high. How did you adjust the mixture?
Hello, yes, I adjusted both float levels and set the mix with a v.gauge.

HioSilver: Yeah, I remember that valve in front of the throttle linkage on the 4100's. You may be right about this Holley needing one.

Guys, the problem may be that I have an open vacuum port for the hot air choke. How should address that issue? Does anyone run a hot air or thermostatic choke? Thanks.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
RA122524
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
7
Mar 27, 2015 03:23 PM
F-250 restorer
1973 - 1979 F-100 & Larger F-Series Trucks
3
Jan 14, 2014 11:22 AM
drive_old_ride_new
Fuel Injection, Carburetion & Fuel System
8
Dec 3, 2004 01:43 PM
ridgerider3
Ford Inline Six, 200, 250, 4.9L / 300
9
Jun 24, 2004 05:42 PM
rusty68
1967 - 1972 F-100 & Larger F-Series Trucks
4
May 30, 2001 08:57 PM




All times are GMT -5. The time now is 11:17 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE