I'm thrashing like most folks to get things done to be able to drive my 66 Galaxie 352 to the Roundup. I managed to repair the busted radiator, get the ignition working properly and swapped in a Pertronix. I THOUGHT I got the carb worked out. I rebuilt the Autolite 4100 a month ago. The car runs fine at idle and I have driven it short distances some times and it seems to be running well until a couple of weeks ago when it died on me and fuel was pouring into the rear ventura. This of course floods it and causes it to die. I replaced the float and I thought I fixed the problem. It ran fine sitting in my driveway for 45 minutes. No sign of the fuel problem. Last night I drove it down the street to test it out since it was running so well. I didn't get 100 yards on the main street until it started choking and died. I had to floor the throttle open to get it to start again. I managed to get it back home and watch it run briefly. Again, gas is just pouring into the ventura from the air horn that hangs over the barrel and pooling in the rear barrels. That which seeps past is flooding it out. So I have a new fuel pump laying around and a new filter and I replace both of them and try again. Same thing happens. I pull the top of the carb off and remove the needle valves and seats from front and back to examine. These are new from the kit. Part of the reason I rebuilt the carb was because of this same behavior. It appears that the floats cannot keep the valves closed, but they were set according to specs. Both needles and seats look perfect. No trash, burs, or anything that I can see that would cause this. I am stumped. Only thing I can figure is to pull the carb all apart again blowing everything out and re***emble AGAIN. The only parts I could not remove before were the jets because I didn't want to chew them up with a screwdriver.
Think the floats are hanging up on something. The angle that the needle valves hit the floats may be off. If you want to send it to me I will have a go at it and send it right back. You could also drive down but postage is cheaper.
Frank. You may have a vacuum, air leak? I am having the same problem with my carter on my flat 6 and the damn thing is rebuilt. It will run good and then it just slowly starts dying like it is starving for gas. I prime the carb and it fires right up. Go figure. Safe measure. Just replace all the gaskets. Check yer float level too. KNUX!
If you can check the feul presure from the pump. Install a pressure regulator if needed. Prolly set to about 4 lbs. Also see if you can get a set of NEW floats. Sounds like a sinking float to me. Or put an Edelbrock on it! jerry
I agree with Jerry--even if it is a stock pump, sometimes a regulator is neccecary-I have seen a mechanical pump out of the box make 9 p.s.i.! and it was from auto zone! it could also be heat related...if the fuel line touches the block or another heat source, the fuel boils in the line, which up's the pressure--on both sides of the problem! makes it a ***** to "re-prime" the lines, and blows the heedle and seat open. I agree with jerry on one other thing...put a HOLLEY on it!
Went through this ordeal trying to make a Quadrajet on a Chevy V8 work right many years ago. Ran really well for a day or two, then it would start dumping fuel everywhere, stallling, etc., went thru the carb 3-4 times ... called the local V8 guy and told him my story. First thing he asked me was "what kind of pump is it ?" ... I knew the owner had changed the pump trying to fix it himself, so I looked in the trunk for the old pump,and found it in the Airtex box the new one came in. My V8 guy starts laughing and told me to put my gauge on it just for the hell of it. It buried my 10 lb. SW, so I hooked up the 0-50 lb. I used for VW type III injected cars, and got a reading of 18 1/2 lbs ! He told me to go buy an AC from the Chev dealer and call him back if I had any other problems ... 302
sonofa! The floats are both NOS btw. So I get out there and hook up a pressure gauge. I could not find a T fitting so I just connected it directly to the pump and connected a remote starter switch to the starter solenoid and cranked it over several times. I pegged my 6 lbs gauge. So I grabbed a 10 lb guage I have and tried it again. It pegged the needle then came down to 8 lbs. I tried the same test several times. Will connecting directly give an accurate reading or does it have to be "T"d in? Anyway, my Motors manual shows that nearly all engines should be between 4 1/2 - 6 1/2 lbs. None between 58 - 66 Ford engines should ever be over 6 1/2. SO what changed? A couple of things. Well, several years ago before I lost interest and money when I was working on it, I replaced the fuel pump because the one I had was beginning to leak around the crimped edge. I believe I just bought one from Autozone. I also removed the stock Ford fuel filter that screws into the carb and installed one of those fancy chrome and gl*** see-through filters. I worked on the car some and drove it short distances in the neighborhood. The same problem occurred a time or two but I didn't pursue it because of other work that needed to be done. Here is what I learned: Murphy is an jerk The stock screw in Ford fuel filter "may" have helped regulate the pressure if it is more restrictive. The planets aligned just right so that I ended up with two bum fuel pumps. One bought at Autozone in 1999 and another one bought at O'Rielly's in 2005. The O'Rielly's was a Federal Mogul, but apparently its another great brand that is now foreign made ****...built by Murphy. Rather than have to install and test pump after pump, I'm thinking my best bet is to just install a regulator.
I haven't done an Autolite 4100 in a while, but I did a 2100 two barrel resently and there was a wire spring that when the needle and seat ***embly and float are put together this little spring affair limits the amount of travel the float has. If it's not clipped on correctly the float rises and lifts he needle off the seat and never stops fuel flow. It's kind of hard to describe without pictures, and again this was on the two barrel, but the two and four barrel carbs are basically the same. Your carb kit should have an exploded view of the needle and seat ***embly. Hope this helps.
I can help with one part, the carb works fine in the driveway because that's the low speed jetting. And that should prove the floats are fine. You get into trouble when you drive around and put the other parts of the carb to work.
Are you talking about the spring that is more like a wire retainer that clips the float to the valve seat? Or another spring that appear to lift the float a little? I have the retainer springs on, but I lost one of those springs that seems to help rise the floats. I couldn't tell which way its suppose to work. I figured it was to help lift the float a little. The pressure is so light, I didn't know how crucial they are. I was told by a supposed reliable source on these carbs that they weren't essential. I forgot all about it till you mentioned it. Now....where the heck to find one.
Yes, the wire retainer that clips the float to the valve seat. If it doesn't go on all the way (till it snaps) it will lift as the float rises. With the carb top removed lift up on the float with your finger, it should stop. If it doesn't its not snapped all the way on and the float will lift out and off the needle seat. If it's like this it will cause the fuel to flow over into the venturi as the car is running. Something else to check if you have the carb top off is to make sure the top of the carb is not warped. It needs to be flat or the gasket won't seal. I had this happen on a later model Motorcraft carb, and had to replace the top to get it to stop leaking over. Good luck.
hey got a 67 390 that did same thing with a stock 2 barrel decided to put a 4100 on it new rebuilt still had same problem you got==bought new edelbrock overflowed at idle lowered the floats worked half *** to shop I bought carb from checked fuel pressure=it was 12 pounds from rebuilt fuel pump installed a pressure regulater set it at 3.5 lbs works as good as new now
Geez, back to the drawing board. I hooked up a gauge and got 8psi from my pump. I bought an adjustable regulator and installed it, set for 5 1/2 lbs. My Motor manual says 4 1/2 to 6 1/2 is in spec. I also discovered the rear NOS float I recently bought was leaking. I could actually hear gas slosh in it when I shook it close to my ear. Bought a new one at Napa. I figured I finally got all of it worked out. Both of these I figure were solid causes for what I was experiencing. It ran so well in the driveway and around the block, I decided to drive it to get it inspected. Long story short, it would not stay running once I got there. This was only 2 miles from home. As I was leaving it stalled out and had to push it to the side. AGAIN the freakin carb is flooding out the same way. Here are some pics of the carb apart. Not sure if anyone has any ideas. I took it apart again so that I can clean it and blow it out all over again. Doesn't look like I'll be driving the Galaxie to the roundup. This problem occurs intermittently. Sometimes within a block of the house, sometimes I can drive 10 miles with no problem. I just can't trust it right now. Red lines point to where the fuel starts to flood in filling up the barrels. I have adjusted the float every way I know how. Only other idea is that maybe 5 1/2 lbs may still be too high.
It wouldn't hurt to run the regulator at a little lower pressure. The pump is prolly putting out a bit higher pressure when the engine is at higher oRPM's than at idle. Set the reg. for 3 1/2 #s at idle and do a test drive. jerry
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