By mercoupe50 - 11 Years Ago
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I have an E-code Bird with a 2x4 setup. I cannot get it to idle below 1000 rpm even with the linkage disconnected. The timing is spot on. any suggestions?
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By Ted - 11 Years Ago
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Assuming you have the original List #1434 and/or #1437 carburetors, then vacuum leaks are at the top of the list. Retrofitted single four barrel carbs can create some problems of their own. Vacuum leaks can occur at the carb spacers, intake gaskets, or vacuum driven accessories. Assuming you’ve eliminated vacuum leaks as the culprit, then the throttle blade alignment within the throttle bores would be high on the list. If the blades have been removed during a past carb rebuild, then there’s the possibility that they were not properly seated within the bores during the tightening process.
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By NoShortcuts - 11 Years Ago
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Welcome to the Forum. 1st As Ted stated, check for vacuum leaks anywhere related to the intake manifold and the mounting of the carbs
2nd From John – the Hoosier Hurricane ~ 3 months ago… -these all relate to the carbs having been apart a. Were the carburetor throttle plates removed during overhaul? If so,maybe one or more of them is not centered in their bore, causing the throttle to be held slightly open. b. How is the fit of the carb. throttle shafts in their bores? Worn shafts and bores admit extra air as well as not letting the throttle plates close correctly.
c. Check to see if the carb. fast idle cams are holding the throttles open. d. The little wires that ride in the slots of the secondary throttle arms. If they were "opened up", making them longer, they can bottom out at the top of the slot and prevent the primary throttle from closing completely. Hope that combined with Ted's suggestions this helps. 
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By mercoupe50 - 11 Years Ago
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Thanks for the replies. I had both carbs overhauled. The front carb sticks when the throttle plate is closed but only the first time when it is cold.. I sent it back and the guy said that it has to be adjusted slightly open. (sounds fishy) I can close it and the idle is still fast. I will check for proper alignment. I will also check for vacuum leaks.on the manifold.
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By NoShortcuts - 11 Years Ago
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I'm careful in rebuilding any carburetors to be SURE in centering throttle plates in throttle bores if I've removed the plates and the shafts. I use a light bulb on the opposite side of the throttle plate to carefully position (center) each plate in the throttle bore. The same amount of light (IF any!) should show around the circumference of the plate in the throttle bore when it is in the closed position.
IMO, any binding in the movement of the throttle shafts (whether cold or hot) is a good indicator of a throttle plate misalignment issue.
Charlie Price, owner of Vintage Speed, specializes in 3x2 set-ups using (among others) the old Holley 94 type two barrel carburetors. He actually sells bases for the 94 end carburetors with the throttle plates finished with a 12 degree angle on their edges so that they seal better than the original 5 degree plates do. Vacuum leaks can KILL idle quality on multiple carb set-up. ________________________ The thread I referred to previously where John (Hoosier Hurricane) replied was dealing with EXACTLY the same issue. High idle on an 'E' dual quad set-up. Throttle plates were THE issue. Tony's idle speed dropped from 1200 to 600rpm after adjusting the throttle plate position in both of the carbs he had previously just rebuilt himself.
Let us know how you make out with this.
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By Ted - 11 Years Ago
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While checking for proper seating of the blades against the throttle bores with a light, also check that one or more of the blades were not installed upside down. The blades do have a chamfer on their edges to aid in sealing them to the bores and if the blades are installed upside down, then the reduction in idle speed gets difficult to achieve.
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By Kahuna - 11 Years Ago
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I run 2 series 4000 carbs on a Flathead Ford and have the same issue. It's caused by the secondary blades NOT being lite-tight. In my case I need another better carb, but if you have the real 2 X 4 setup, your best bet is to send them to Mike Suter in PA. I got his name from this forum. HE is the absolute best resource and just the most helpful person I've run across. Call him @ 215 757-3678 He'll be more than happy to chat with you
Regards Jim
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By mercoupe50 - 11 Years Ago
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Thanks for all of the replies. I will make the light test and see what I have. It may be a few days as the storms have set in.
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By mercoupe50 - 11 Years Ago
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I checked the throttle plates on both carbs. All had more light on the side perpendicular to the shaft.. I adjusted them for less light but could not get equal light. None of the plates were upside down. The plates seemed to seat properly and not bind. I am not optimistic that the amount of adjustment will solve the problem. I will try to get around to firing it up tomorrow.
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By NoShortcuts - 11 Years Ago
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Sounds like a possible solution to your high idle problem. Hope so! If, as you said, all the throttle shafts will turn so that the throttle plates seem to close so as to seat in their bores, that's GooD! ________________________ I'm trying to think of possible variables in carburetor rebuilding work... - For many years in production engine assembly, pistons were selectively fit because of machining variations. - Your carburetors have likely been apart more than once since they were produced ~57 years ago. - I wonder IF the throttle plates were originally selectively fit in Holley 4000 carburetors when they were manufactured? - IF the throttle plates were originally individually fit, I wonder how meticulously someone kept track of their original locations when they were torn down and reassembled over the past 5+ decades... ________________________ Let us know how you make out! 
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By mercoupe50 - 11 Years Ago
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By centering the plates I have managed to get the rpm down to a little over 900. I checked the intake manifold gaskets with oit with negative results. A strange thing is that the rpm is about 700 when the choke opens and the increases to about 900 when fully warm. There is no interference with the fast idle cam at this point. I have found that with a gasket problem that it shows itself prominently when the engine is cold and then reduces dramatically when the engine warms up. I am stumped.
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By Ted - 11 Years Ago
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Stock camshaft? If so, then what’s the overall condition of the engine? High mileage? For whatever reason, the blades being removed during a carburetor rebuild ends up being problematic in getting those aligned back in the bores properly. If you are still getting light in the throttle bores with the blades completely closed, then that’s still a problem to be dealt with.
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By mercoupe50 - 11 Years Ago
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So if I get light on the top and bottom of the bore does that mean that the bore or plate is out of spec? The cam is stock for that engine with 50K original miles.
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By Ted - 11 Years Ago
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mercoupe50 (11/9/2014)
So if I get light on the top and bottom of the bore does that mean that the bore or plate is out of spec? ........ Without looking at your carbs, I would still say Yes. When all is right, there should be no light coming through those bores 90° to the shaft. As a general rule and true for all carburetors, the blades should not be removed from the shafts unless there’s an obvious problem in that area. I end up repairing or correcting a good number of carbs that have had the blades removed for no reason other than that there were screws there that could be removed. In some cases, the blades must be returned to the same bores in which they were removed. With them installed in different bores, they simply don’t align up properly for a variety of reasons.
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