Carb issue. Take a look.

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Badart

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This 600 cfm Holley vac secondary carb is recently rebuilt and have been running it on my dart with no problem. I have recently installed it on my truck with a stout 318 and a 4 speed and have found that the truck has a dead spot right after squirters stop from 1,500k-3k rpm. The fuel just kind of dribbles out of the boosters as you can see in the video and causes the truck to buck until the secondaries open. I have looked for a vacuum leak, but have not found one. Any idea what could cause this issue? Should I just look for a 4150 with mechanical secondaries for my 4 speed or just rebuild this again? [ame="http://www.youtube.com/watch?v=aZ_jG7fweQ0"]YouTube - Carb.mov[/ame]
 
I have been running Holley carbs for 25+ years.

I use the same routine every-time I have a problem.

1. Recheck the float levels.

2. Hit all the air bleeds with a spray carb cleaner.

3. Remove the needle and seats, hit with a spray carb cleaner, then reinstall.



For you I would also

1. Toss in a new pump shot diaphram

2. Pull that squirter and make sure it has a gasket and the the needle under it is there and not sticking (hit this area with a spray carb cleaner too).


You don't need to rebuild or get a new carb.
 
1968FormulaS340 said:
I have been running Holley carbs for 25+ years.

I use the same routine every-time I have a problem.

1. Recheck the float levels.

2. Hit all the air bleeds with a spray carb cleaner.

3. Remove the needle and seats, hit with a spray carb cleaner, then reinstall.



For you I would also

1. Toss in a new pump shot diaphram

2. Pull that squirter and make sure it has a gasket and the the needle under it is there and not sticking (hit this area with a spray carb cleaner too).


You don't need to rebuild or get a new carb.
Click to expand...

Thanks 68Formula I have already bought another full rebuild kit and a couple of cans of carb cleaner and plan on tearing it apart tomorrow. It has been a great carb, but since I put it on this truck it has been a nightmare. I run two filters and a screen before the carb and when I pulled the float bowl today there was crud in there. The only reason why I ask about going to a 4150 style carb is because that is what most people run with a stick, correct? My truck is geared to run at 1,500 rpm at 60mph and I want my secondaries to open at that rpm if need be to help pull these hills around here.
 
Defiantly wouldn't put another carb on it until you get all the "crud" out of the fuel system.

Mechanical secondaries vs vacuum is a debate that can go on for days around here.

This is my personal opinion.....

I would stick with vacuum secondaries for your truck. With the correct secondary diaphragm spring it will do what you are looking for and more than likely return better fuel economy.

Buy this.......

http://www.summitracing.com/parts/CMB-03-0100/
 
Badart said:
Thanks 68Formula I have already bought another full rebuild kit and a couple of cans of carb cleaner and plan on tearing it apart tomorrow. It has been a great carb, but since I put it on this truck it has been a nightmare. I run two filters and a screen before the carb and when I pulled the float bowl today there was crud in there. The only reason why I ask about going to a 4150 style carb is because that is what most people run with a stick, correct? My truck is geared to run at 1,500 rpm at 60mph and I want my secondaries to open at that rpm if need be to help pull these hills around here.
Click to expand...

well you didn't mention is it was a vac secondaries or mech... guessing vac since you want the secondaries to open as stated...

that just depending on the spring you install that times the secondaries opening...
 
Thanks guys. I do have a few spare springs laying around and will try them after I clean up the carb. I will post the results once I'm done.
 
Well she is running good now. Gave the carb a quick cleaning, gasket set, set the floats and now it runs like it should. I also installed a lighter spring in my vacuum secondaries and now they will open when I mash on it in fourth gear turning 1,500 rpm. Thanks again.
 
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