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By BFOOTER03 - 16 Years Ago
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I got my 3x2 set up on the engine this weekend but ran into a couple problems and need help and advise. First of the engine was running great with a single 2 barrell and idled at 700-800 before I did the swap and I am runnign the 2 barrell as my primary carb with the 3x2 set up. Only other changes are I replaced my vacuum line from a hard line to a soft line. Ran new 5/16 lines with a pressure guage into all 3 carbs. First attempt: After installing the 3x2 the truck runs at 1700rpm and I can not get it any lower. The outer 2 carbs have fuel going to them but the throttle linkage is not hooked up and the butterflies are closed. I have backed the idler all the way out but it still stay at 1700. It also has a high pitched sound similiar to a wishtle at all times. Pressue guage is registering only about 2 lbs of pressure but all carbs difenetly are getting fuel. Seems to me like the outer 2 carbs floats are not shutting of the fuel??? Second attemept: Installed old fuel line only to the primary carb but still am having problems. I can get the idle down to 1100-1000 but not much lower with out it choking out. When I rev it up it and release the throttle it is slow to back down and the high pitch whistle starts. Timing has been rechecked and is at 10-12 deg advanced. I have a couple videos posted that might help. Thanks Bing http://www.youtube.com/watch?v=0gVv5UDJj8g http://www.youtube.com/my_videos_edit
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By charliemccraney - 16 Years Ago
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The whistle probably indicates a vacuum leak. Do any of the throttle shafts wiggle around?
Something else you can try to ensure at least that your old carb is still functioning correctly or that there is not another problem is to remove the end carbs and block of the manifold with a plate of aluminum or steel. See if you can get it to run with just the one carb.
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By Pete 55Tbird - 16 Years Ago
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Bigtime vacuum leak. What manifold, which heads?
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By BFOOTER03 - 16 Years Ago
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Pete I am running an Edlebrock 573 with G heads. Charlie I will try and cover the outer two carbs tonight and see if that corrects the vacuum leak. Any trick I can use to try and locate the leak if blocking off the 2 carbs does not help?
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By charliemccraney - 16 Years Ago
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Don't simply cover the carbs. Remove them from the manifold and block off the opening at the manifold. This will completely eliminate the other 2 carbs from the equation and make it much easier to narrow down.
I'm always thinking too much. Because you can hear it whistling, it may be easy to spot by listening closely around the manifold. Try that before removing anything.
It reminds me of Dennis' truck last year. It had a leak somewhere. I'm sure he'll chime in.
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By mctim64 - 16 Years Ago
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Bing, Holley 94s have a bad problem with warping the bowl and not getting a good seal with the base. Also if it is dumping fuel (don't think this is your problem) the rebuild kits on the market don't always have the correct power valve in them. They look the same as the later four barrel valve but they are not, the 94 valve has a small round hole and the later ones have a long slot that wont seal on the gasket.
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By BFOOTER03 - 16 Years Ago
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Tim, I sanded the carbs down as you mentioned but you know how my mechanical skills are at times. Killer, thanks for addtional ideas. I had not done the carb spray but will tonight along with the other ideas. I am leaving for a show this weekend and I am hoping on taking the truck. Hope the neighbors don't mind if I have the truck running into the wee hours of the night.
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By pintoplumber - 16 Years Ago
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Did you plug the idle circuits inside the end carbs? Mine whistles sometimes, I don't remember hearing it this year. My guess would be the throttle shafts. Mine idles at 700 except when I'm racing.
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By BFOOTER03 - 16 Years Ago
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Sprayed wd-40 along the runners and at the carb bases but the idle did not increase. Ended up pullng and the carbs, intake. Put the old intake back on with the center carb from the 3x2. Everything is back to square one and running fine. Only adjustmented was the odler screw. Got a show in MI this weekend so time did not allow for very detailed problem solving but I will try again. Next time it will be with just the intake, the primary and block of plates. Problems are easier to solve when you make only a change or two at once. One mans problems is another mans lesson on what not to do. Thanks for all the ideas. Bing
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By pintoplumber - 16 Years Ago
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If you haven't blocked the idle circuits in the end carbs, they will be getting too much fuel. When you get back let me know and I can walk you through it.
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By pintoplumber - 16 Years Ago
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Bing, here's what I can tell you. Take the air horn off the top of the carb. It looks like this. 
Remove the 4 screws and pull the parts out so it looks like this. 
Cut 2 gaskets out of some thin material about 5/16" diameter and place them here. 
Reassemble the carb with those passages blocked.
Between the carb and the base is the power valve. Unscrew it and replace it with a plug. I used a Mr Gasket Co. #1510. The power valves can leak fuel so eliminate this possibility.
For a couple of years, I ran with just fuel to the center carb. No block off plates, just kept the butterflies closed. Adjusted the progressive linkage so only the center carb would work.
When I felt more comfortable with the set up, I turned the fuel on to the outside carbs [I have little ball valves] adjusted the linkage so they all work. I went from 19.80 to 18.31 and this year I had an 18.19. I'm running a 239.
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By BFOOTER03 - 16 Years Ago
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Dennis, thanks for the suggestions and apprecite the pictures. I think I will take your approach and go from there.
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By BFOOTER03 - 16 Years Ago
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Finally got around and put the 3x2 intake on. Blocked off the end 2 and it ran fine on the center carb with no vaccum leak. With the front block off and a carb on (no fuel if going to the carb) it started fine but ran like crap. There was not whistle sound but it was not smooth running at all. Did some popping and would only runn with my foot in the gas. I did not check to see if a plug wire came loose as the thought did not occur to me until later. Question is should it not run fine with all 3 carbs on (none of them blocked off) and only having fuel to the primary carb? Thanks Bing
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By pintoplumber - 16 Years Ago
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Bing, sounds like it's getting air through the end carbs and running lean.Are the butterflies closing tightly? When you held a carb up to the sun with the butterflies closed, could you see any light coming through?
If they don't close tightly and you had fuel to them before, that's probably why you couldn't get it to idle below 1700 or so.
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By BFOOTER03 - 16 Years Ago
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Dennis closed the butterflies and it ran fine. You are a GENIUS. Thanks. Should have read the thread again as you made mention earlier about keeping them closed. Will try it tonight with all 3 carbs on. I think I am making progress.
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