| Flatbob | -- 04-04-2010 @ 7:55 PM |
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Plugs are still wet & sooty looking; have installed new power valve & idle mixture screws to no avail. Anyone recommend a carb. specialist I could ship to, have heard that someone made a test device that could measure "leak down" on the power valve.
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| 37RAGTOPMAN | -- 04-05-2010 @ 6:42 AM |
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FLATBOB what year engine and what make carb, was wondering if you looked directly down the carb, when running do you see any gas running down inside the carb,the float level could be to high, also is the float good, not filled with gas,?? I assume the ignition system is good and ignition wires are good, did you rebuild the carb ? fuel pump, how did it run or what did you do different that maybe made this run this way? choke is all the way OFF, are you running a electric fuel pump ? maybe to much pressure, adjust to specs, I think spec should be 3 - 4 lbs, need more info, There a few good carb rebuilders, in the club,[advertise in the V8 TIMES } also parts CELLAR in MASS can help you on this also but you have to be sure what the problem is before you relace many parts, my 3 cents worth 37RAGTOPMAN
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| Flatbob | -- 04-05-2010 @ 7:26 AM |
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Ragtop, will look down carb. throat while running & see if any excess fuel visible. I rebuilt the carb. as far as I could with available rebuild kits, adjusted float level as described in instructions but will recheck. Ignition system gives good spark to all cylinders. Engine idles very smoothly at slightly under 700 rpm, good throttle response in low & midrange, doesn't overheat. Thanks for responding.
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| TomO | -- 04-05-2010 @ 10:33 AM |
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Flatbob, do you have the power valve with the machined surface and did you tighten it to 15 ft lbs? The seating surface for the power valve on your carburetor may be corroded or not perpendicular to the threads. It will require a machine shop to correctly reface the seat. Tom
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| Flatbob | -- 04-05-2010 @ 1:13 PM |
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TomO, Not sure about mating surfaced being machined but will pull it & check. I just installed it screw driver tight, but will go to 15lbs. when I put it back. Thanks, Bob
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| TomO | -- 04-06-2010 @ 8:20 AM |
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If you have the power valve with the ribbed sealing surface, I have been able to seal them using a fiber or plastic oil pan drain plug gasket. They are thicker than the kit gaskets. Tom
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| Flatbob | -- 04-06-2010 @ 9:32 AM |
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TomO, here's a cpl. more symptoms that might help in diagnosing the over rich condition: Engine continues to run although rough with idle screws all the way scr*w*d in, first start of the day will fire right up, restart within 10 minutes with foot slightly on gas pedal carb. instantly floods. Will get the carb. off car today. Thanks, Bob
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| supereal | -- 04-06-2010 @ 10:27 AM |
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You need to run a vacuum check. If the idle screws don't affect operation, that is a place to start.
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| Flatbob | -- 04-06-2010 @ 11:11 AM |
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Super, am getting 17" & cylinders very 70-90lbs. This is a new engine with 98 miles on it, am wondering if rings haven't seated yet because it's running rich?
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| Flatbob | -- 04-06-2010 @ 11:15 AM |
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TomO, power valve is .065 with smooth seating surface, should I use two gaskets together instead of one? Don't have a way to measure torque on power valve but will make sure it's in tight.
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| supereal | -- 04-06-2010 @ 2:14 PM |
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It takes a couple of hundred miles of driving at varying speeds to seat the rings, unless you are using synthetic oil, in which case, they may never seat. I wouldn't expect that to be a problem. Your vacuum is good, and the compression is a bit less than I would expect with a recent rebuild, but it may increase as the rings seat. If not, I'd run a wet/dry compression check to see if there is a valve problem. As noted earlier, a leaking power valve can cause a rich mixture, particularly if the base doesn't seat on the gasket. It is also possible that the valve is incorrect. Good power valves carry a number stamped on the side. Usually, a 6.5 is used. This indicates the vacuum level where the valve opens to admit extra fuel, such as full throttle, or long pulls, where the manifold vacuum falls. To see if the valve is simply leaking, pull the carb, fill the bowl with gas, set it on the bench overnight and see if it leaks down.
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| Flatbob | -- 04-06-2010 @ 3:09 PM |
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Super, since lowering the float am getting 15-16" at idle, 0-23" open & close quickly and 18" at high engine speed. The engine has 99 miles on it.
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| TomO | -- 04-07-2010 @ 9:43 AM |
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Never use 2 gaskets to try to seal mating surfaces. It just doesn't work out. If you don't have a torque wrench, select the gasket that fits the machined surface of the carburetor and tighten the power valve 1/8 turn past were the power valve seats on the gasket. Then fill the carb bowl with enough gas to cover the power valve and let it sit for 1 day. If the gas leaks out, tighten the power valve a little more and recheck. Make sure that your float gauge is perpendicular to the float and the gasket surface when you set the float level. Your idle screws will have little effect on idle mixture if you are leaking gas past the power valve or the float is set high. Tom
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| supereal | -- 04-07-2010 @ 10:16 AM |
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The float level shouldn't affect vacuum reading. The power valve opens to enrich the mixture when the manifold vacuum falls below a certain level to address heavy loading at or near full throttle. Are you running the old style distributor with weight advance, or the later "posthole" vacuum advance type?
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| Flatbob | -- 04-07-2010 @ 2:10 PM |
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TomO, don't have a float gauge, the gauge is no longer included in the repair kit, instead they provide a measurement of 15/32" from top of casting to lowest point on top of float & this is what I've done. The car seems to run ok but have no experience driving another flathead V8 to make comparison. Thanks for the help,Bob.
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| Flatbob | -- 04-07-2010 @ 2:16 PM |
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Super, I think I probably read gauge wrong when I said 17"'s. It's realy 15"-16"'s. I have the old crab style distributor. The car runs reasonably well & I guess I should be happy with what I have, perhaps if & when the rings seat it will be even better. Thank you for the help.
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| supereal | -- 04-08-2010 @ 7:50 AM |
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Setting the float level isn't a big deal, but it is made easier with a reliable gauge. I am attaching a scan of a gauge I made from part of an oil can almost 60 years ago when I worked for a Ford dealer. I've included a ruler so the size can be accurately translated. Just remove the carb airhorn, turn it upside down, and bend the needle tab until the float just touches the gauge.
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| Flatbob | -- 04-08-2010 @ 9:10 AM |
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Bob, thanks for the gauge template. Again, you have helped me numerous times in the past, thank you. Bob
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| TomO | -- 04-08-2010 @ 10:14 AM |
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I would make a small modification on Supereal's gauge. I would make the bottom tab about 1/2" longer and then bend it to give a better seating on the gasket face. See next post for photo. Tom This message was edited by TomO on 4-8-10 @ 10:15 AM
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| TomO | -- 04-08-2010 @ 10:16 AM |
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Here is a photo that will work with the forum. Tom
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| Aloha40dad | -- 04-08-2010 @ 12:47 PM |
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Flatbob, I've been following this discussion as it also pertains to what we are going through. I didn't see the carb model that you guys are trouble shooting. John
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| TomO | -- 04-09-2010 @ 8:10 AM |
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John, the advice given on this thread applies to all Ford model 94 carburetors. This includes the 91-99, 21-99, 59 8BA, etc Tom
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| Aloha40dad | -- 04-09-2010 @ 12:40 PM |
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Thanks for the come back, Tom. This thread was really a great tool. I'm sure we'll get the details taken care of with all of you guy's great help. If ever there was a need for a sight like this, it's out here in the middle of the Pacific Ocean. Talked with Charlie Price and Skip in Florida and am hoping a few boxes will be arriving today. Got a kick out of your ribbing a certain photographer on another thread. Keeps this stuff personal and that's one of the joys of communicating with you guys. Thanks again. John
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| Flatbob | -- 04-09-2010 @ 4:04 PM |
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TomO, thanks for info. on template, will make one in a day or two, got some yard work to catch up on now with the good weather.
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| Pauls39 | -- 04-09-2010 @ 5:52 PM |
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A Vacuum gage reading 14-16 could indicate late ignition timing. Check your points to make sure they are still set correctly. Next check the timing.
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| Flatbob | -- 04-10-2010 @ 9:42 AM |
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Paul , thanks for responding; will check timing. Bob
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| Flatbob | -- 04-10-2010 @ 9:43 AM |
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Paul , thanks for responding; will check timing. Bob
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