Hey y’all I have a old school Holley 4160 carb that came with my 302 when I bought it. I bought a rebuilt kit for it, rebuilt it, and put it back together the way I took it apart in.
Well even though my friend is a Holley freak and his dad is a weekend mechanic, we can’t figure out why my carb has a massive dead spot right off of idle. In order to get her going so she won’t die on me when I’m getting going, I have to feather the gas then I can let out of my clutch and hopefully get going without a whole lot of bucking. Ha ha get it Bronco, bucking, ha ha.....
Anyway we screwed with the float levels and got those right...al least the primary float level. The secondary float is sticking and pukes fuel out the fuel delivery tube but I purchased a new fuel delivery tube and out it on there and that problem is solved.
However we can not for the life of us get the dead spot to go away. Luckily enough my friend has a whole shelf full of 4bbl carbs is his room and let me barrow one till I can get mine fixed or get a new one out’a the box....
Any ideas guys on why my carb has such a massive dead spot and any ideas on how to remedy that lil problem? Thanks

 

It is an accelerator pump issue.
With the engine off look down the carb and open the throttle and verify that gas is spraying out of the discharge nozzle.
Also make sure the the accelerator pump cam is installed properly (colored plastic piece on linkage) and that the pump arm moves as you open the throttle.
Try these and let me know what happens.

 

If the cam is there its probably out of adjustment or the arm is bent which is about the same thing, It has to be squirting fuel the instant the throttle moves..

 

okay guys an update:

I put my carb on (the one I'm running now is on loan from my buddy) and it squrts fuel when the throttle is opened up but there is still a dead spot off of idle and she is a real bee-och to start as in just cranking over and an occasional spike like she wants to but can't kind of a thing.

 

Give the timing a check. If it is the accelerator circuit you might need to add fuel or change the pump cam configuration.

 

Does it start to squirt fuel as soon as you start opening the throttle?

 

Yes she does which is the weard thing. Should I back the jets on the meatering block out all the way and then try to start her and just keep adjusting the jets 1/2 turn in till she starts and runs like she should? Or is there another aproch?

 

Turn them all of the way in, then back them out until you get the highest idle. I don't think that this will help the bogging down though. It may be squirting too much fuel. What is the number on the squirter nozzle?

 

not sure. But I know its not a 50cc acclerator pump though.

 

Whats the list # on the air horn of your carb? Give me that and I can tell what squirter you should have and other things also.. there are several adjustments on a Holley accelerator pump system, 1. the arm adjustment, its obvious because of the adjusting bolt and spring assembly on the end of the arm, this needs to be set to start squirting as soon as the throttle moves and still have a little play at WOT, around .015 or more I think. 2. the pump cam, there are several ranging from lighter to darker in color, different colors with different ramp configurations to change when and how long the shot will last, try changing the hole the screw goes into and see if that helps, should be 2 sometimes 3 holes to use, 3. and the squirter itself, if its too large or too small you could be bogging from too much fuel to soon or vice versa, when you look in to see the shot, see if it squirts all thru the opening of the throttle or of it starts and stops anytime before wide open. There are other things that will do this but it is usually one of these things I have listed. I have seen some set so tight it has bent the metal plate on the diaphram and that causes a problem too.. so check all these next, and if it still bogs we can check a few other things also, just because you put things back the way they were, does not mean someone in the past did the same thing. but thats for later.. hope this helps.. Also, there is a # on the front of the squirter, with a light and magnifying glass, (or really good eyes) you should be able to read it with the choke all the way open.

 

Okay Thanks for the info the LIST No. is : LIST-9834-1 below that is 2929. The number on the front of the squirter is 31.

 

Thats a universal 600 cfm and the right squirter for it too, if none of this works, check the base plate for warp or cracks, a vacuum leak could do that also, make sure the little gasket between the electric choke and the housing did not fall out when you put it together , it happens sometimes.. make sure you got the right base gasket in too, if you had more than one to chose from there is little difference in them but its enough, not sure after this, only so much one can do without hands on if you know what I mean.. but will keep trying till you get if possible!

 

okay. I checked the base plate and it is not worped. I checked the gaskit for the choke housing and that is okay. I checked the rod for the acc pump and as far as I can tell is aint bent. I moved the screw for the pump cam from the No. 2 to the No. 1 hole and I looks like it helps some...now I just need to put it on her and see if that works. *crosses fingers and hopes!!*

Wish me luck. I'll keep y'all posted!!

BTW is there any way to take the choke off completeily? or would that mess the vacuume up?

 

A manual choke setup will block the vacuum port if you want to switch to one of them, personally I like electric but its whatever you like that counts! I hope these things cure it also, I'll check back later and see if it did, Good luck!
Also, did you check for clearance at wide open throttle on the accelerator pump? Should have a little play that the pump arm will move when holding the throttle open and should squirt as soon as the throttle moves from idle.. Hope it works!

 

Should have .015 play at WOT