A little help here, On My 8BA flathead my 94 carb only works with the choke almost closed at all times. When it gets to normal temps, I open the choke and it will stall out when I stop. The 94 is set with 1 1/2 turns out fuel and air mix. The idel is set all the way out. I closed off the va***e line as I'm running Bubba's chevy converted distributor with it timed 600 rpm at 4 degrees and 2500 rpm's at 24 degrees. Why is the 94 needing to run so lean? What am I doing wrong?
what is engine vacuum? what is fuel pressure? what is fuel volume? is fuel clean and fresh? if all are good, i would suspect plugged up carb, most likely from gas deposits...jack
I'd suspect a vacuum leak and spray some starting fluid around the base of the carb to find out where the leak is. Air is getting into the intake upsetting the fuel mixture after it leaves the carb. The closed choke makes up for the added air.
Sounds to me it isn't getting enough fuel. the choke restricts the air back to match the volume of fuel - like if you are getting enough fuel to support less than 100cfm. I am still learning the holley 94 but i am thinking 1 1/2turns out should make the idle circuit overly rich (i know a lot of guys think that that is where it is supposed to be but generally 3/4 is about right), so that tells me the carbs is asking for all the fuel it can get because it don't have enough. The float would be a good place to look, take the top off and see how much fuel is in the bowl - it should be considerable. Turn the top upside down and the float should be about level for a ballpark check. You are looking for a big item, if the float is off by a few thou it won't matter. Look for trash in the bottom of the bowl, it easily gets into the main jet/well in a 94 and just 1/2 of the carb will be working. In the venturii the wells are removable with 2 sets of screws and straps, take them out and blow carb cleaner thru them - don't worry there are no springs with irreplaceable check balls that go zipping past your ear, just a couple gaskets that you need to keep an eye on. Thats about the whole thing for a quick troubleshoot, again my first thing to check is the level of the fuel. Out of curiosity, the rubber fuel line going into the pump, is that stock? if so it is likely swollen up from the alcohol and needs replacement with modern hose. On the other hand, you just might have to call an exorcist to chase out them demons. Good luck, oj
The flathead and all the parts have 22 miles on them since rebuild. The float is dead on from rebuild and thr float is set correct. The lines and gas tank are new, with new fuel. It does make sence about a vacuum leak being the problem, but so far no luck in finding it.
Don't forget about the vacuum line that feeds the wiper motor. You could have a pin hole in it under the dash. I take a pair of pliers and pinch any vacuum hoses closed to test them.
Both OJ and Tommy are suggesting the normal suspects. Vac leak, dirt hung, or up float valve. If you used a Tomco take a look at the disk in the valve. I've had them get caught partialy closed and closed. If it is a vac leak its a big one. Try spraying carb cleaner at the manifold/block interface to see if things change. How does it run other wise? All cylinders firing?
looks like I found the problem! The base in the back of the 94 has a screw in vacuum line and the washer was worn out, plus it was loose and cousing a major leak. Thanks guys for the info.
Cool thanks for letting us know the outcome. Now others can learn from your problem. If they do a search.
Absolutely the first thing I would try on it. Mine did the same thing and this helped me find and fix it rather quickly.
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