I have the original Carter AFB on my '59 Mercury 430. It was 15 degrees this morning and I swear I pumped it 50 times before it started firing, even with a functioning choke. One thing I noticed when rebuilding the carb was that the new accelerator pump pretty much fell into the bore in the body of the carb. It does still operate, but I'm wondering if it's not shooting an appropriate volume of fuel and instead just bypassing the seal on the piston. So my question is does anyone make a little speedi-sleeve type of thing to go in the pump bore of these carbs? Other than fiddling with the choke adjustment some more I'm not sure what else would make it that hard to start. I just now put a new thermostatic spring in the choke mechanism so I'll be readjusting that after it cools down again. My other junk always fires off after 3-4 pumps even without choke when it's 10 degrees out. So I'm assuming it's gotta be that pump bore since it drives like a Caddy otherwise. Thanks all
Was there more than one accelerator pump in the rebuild kit that's possibly larger? Was the new leather seal dried out from age or was it still pliable? The leather seals will soften and swell slightly after soaking in gasoline for a while. Was there a garter spring inside the leather seal to help press the seal against the sides of the pump bore? If not, did the old pump have a spring in it that you could swap into the new pump?
There was only the one pump in the kit and it had the spring around it to expand it. I had run my finger in the bore and it felt like there was wear towards the bottom vs towards the top. The new pump was tighter than the old one but it still didn't really have much drag even with a drop of oil on it.
Thoughts: (1) The pump only functions in the lower roughly 1/2 inch of the pump well. The upper inch or so is tapered to allow a smooth transition of the plunger. The pump will fall into the top portion of the pump well. (2) An accelerator pump will NOT function at start up if there is no fuel in the bowl. The 2 AFB's on my shop truck, because of the panther p*** currently sold at the fuel stations, will evaporate dry 30 minutes after shut-down. Have you specifically tested the pump function? If not, test by first starting the engine, and you KNOW there is fuel in the bowl. Now stop the engine, remove the air cleaner, open the choke butterfly, look into the primaries, and work the throttle to WOT. You should see two squirts of fuel. If not, something is wrong. If you do, the hard starting is not the fault of the pump. I installed an electric pump wired on an oil switch for permanent power with a manual push button override on the pump to prime the carbs prior to starting. (3) Carter made accelerator pumps for the AFB in 9/16, 5/8, 11/16, and 3/4 diameters. (4) The original carburetor to your Mercury should be a 2853s. The 2853s used an accelerator pump part number 64-205. There is also an internal dashpot that many folks call an accelerator pump (it looks like one) part number 64-196. They are physically interchangable, but neither will function correctly if interchanged. Both are in the kits we make. (5) Possibly "forgotton knowledge" but leather pumps should be treated with a few drops of light machine oil (3 n 1, neetsfoot, or even sewing machine oil) prior to installation in the carburetor. Far more reliable than any of the new "artificial leathers". Mine have been in operation for over 20 years. (6) As we don't use the A/M kits, I have no knowledge of the pump being used. (7) If the accelerator pump inlet check valve (should be replaced when rebuilding) is defective, the pump will simply squirt the fuel from the pump well back into the bowl. Did you check the function of this valve? Jon
I should've mentioned I have an old AC Delco electric pump on the car, and I let it prime up for several seconds before trying to start it. I can see the discharge nozzle squirting fuel when I operate it, so the check valve is operating, I'm just not sure that it's putting out the volume it's supposed to with each pump. If it only puts out 2 pumps worth of fuel after every 10 pumps, that would explain why I have to wear out the pedal to get it to start. I will probably just order a part number 64-205 and see if it fits any tighter. This pump was still falling right in on the bottom half of it's travel, but I don't think so much that the next size up would fit in the bore. I've rebuilt several other old carbs with leather pumps and this one just felt very loose. I did put a drop of oil on the leather before installing it. I will readjust the choke tomorrow when it's cold, if it still won't start I'll order a pump, if that still doesn't change things then I'll report back... Thanks!
If everything is right, should be able to pump the footfeed twice, get out of the car, and start the engine reaching through the window. It doesn't take much fuel. On a personal note, one of the three DUMBEST moves I have made with cars, trucks, etc. in the last 60 years, was to put an electric choke on my wife's car! Jon
I can usually get them to go that easy, this one has just always been rough to get started. Even in the summer it took quite a few pumps so something is definitely off. The very first thing I always do with a carb that has an electric choke on it is pull it off and throw it in the trash. All my cars have manual chokes except this one, which has the original hot air choke. I don't know what goof came up with the electric choke but they cause more problems than just not having a choke at all in my experience.
I readjusted the new choke spring this morning and it started better, but it was also 20 degrees warmer out. As far as the accelerator pump goes, if I work the throttle at a normal pace it will give a pump shot for the first tiny bit of pump travel and then not shoot any more through the rest of the travel. If I hammer on the throttle then it shoots through the entire pump travel. So the bottom of the bore is worn vs the top. I just read that with leather pumps you should run a blunt object around the inside of the seal to break loose any protective sealant that may be on it when you get a new one. I don't remember doing that, maybe I will get lucky and be able to stretch this one a bit and get it to seal. It sure seems like it's the correct size, just has a worn bore... Maybe a neoprene rubber pump would take up the wear better?
I have a manual choke converted carter abd in my merc. Same behavior. I soak accl pump piston with atf and then strecth it gently and put o ring under the lip. Then install it back without o ring. It starts with full choke and few pedal pumps but never immediately.it might be due intake manifold desing? Who knows.
My FEs always start hard below 20 degrees also, always figured it was the intake design. I don't expect it to fire immediately but I can't have it running the battery dead before it even starts sputtering. I'm going to pull that leather pump back out and try stretching it, maybe soak it in some Neatsfoot oil.
Stretching it out carefully should help. I had the same problem on my '65 Skylark's AFB - the pump wasn't working with the engine running for some reason. Someone online suggested that a common trick when rebuilding these back in the day was to very gently stretch the leather before you install the pump - it doesn't take much. Well, that worked and I believe the pump's been in there ever since (probably 10 years or so).
I really don't understand the hard starting on the various Fords you guys are having. Shop truck, Ford 390 with two Carter 625 CFM's running simultaneously. If the temperature is above freezing, turn on electric pump to prime the carbs, pump the footfeed twice (I guess that equals four pumps on a single carb since I have two), pull the choke, and start the engine. It will start on the 3rd or 4th revolution. If the temperature is above zero, same procedure, except 4 or 5 pumps. Again, will start with the 4th or 5th revolution. Leather pumps, been in carbs for about 19 years. Used to drive this truck regardless of temperature, but did (then) put Mobil 1 in the crankcase. Before the Mobil 1, hard starting due to slow cranking. Jon
I do admit, that i havent done full tuneup for my 430.and by that i mean float level, fuel pressure spark plugs etc checks. I have a 390fe 2bbl with electric fuel pump, autolite 2100.i converted it electric choke and adjust it completely. Allmost any freezing temperature few gas pedal pumps and it starts allmost immeditially. I am a fan of electric chokes.mostly because all the hot air choke parts are so hard to find in here. You know, pipes stoves springs.
I stretched the leather pump out, it wasn't looking like it was doing much but when I put it back in the carb it's too tight now. So at the very least I learned how much is too much LOL. I'll fiddle with it more later, working outside in a snow storm and don't want to get even more snow in the motor... At least I know what the deal is with it now. Going to order a spare pump in case I f'd this one too badly. Electric chokes run off of basically time delay only, which is worthless and makes the thing hard to start under most daily driver conditions. And in my experience you have to fiddle with the adjustment every few months with the weather changes. If I can't find hot air parts for something I just hook a manual cable to it and be done.
Take the pump out of the carburetor. Soak it in water for about 30 minutes. Wrap the leather cup with masking tape, with the sticky side out. Let it dry overnight. Remove the tape. Oil it again, and put it back in the carburetor. I am assuming here your electric choke is wired through the ignition switch. If so, try this the next time you go to start the car: (1) Acquire a squeeze bottle (an empty ketchup or mustard bottle like often found in restaurants work great). (2) Empty the bottle, clean, and fill with fresh gasoline. (3) Remove the air cleaner (4) Fill BOTH carburetor bowls by squirting gas into the bowl vents; fill the bowls (5) Replace the air cleaner. (6) Do not turn on the ignition (7) Pump the footfeed 3 times to the floor, and remove your foot from the footfeed (8) With your foot OFF the footfeed, turn on the ignition, and start the car. My thoughts are that when you run the electric pump long enough to prime the carb, the choke goes off, and you have no choke. If I am right, then the solution is to mount a second temporary voltage source to the electric choke. If I have to use an electric choke, I personally wire the permanent wiring on an oil pressure switch, and a temporary push button for priming. Let us know. Jon
I don't have electric chokes, was just commenting on Pontmerc's post. The hot air choke on mine is working great now with the new thermostatic spring. I just soaked down the leather pump with oil and ran it up and down in the carb a zillion times and it seems to be ok now. I noticed in this carb that there's no check ball for the pump, there's just a screw-in orfice that provides enough restriction to force most of the fuel to the discharge nozzles. With the top off the carb some of the fuel shoots up out of that orfice. Not sure if it's normal or if I am missing parts. I'm waiting for another cold morning to retest but it seems like it should be as good as it's going to get now. The pump squirts fuel during it's entire travel now. Never thought to stretch the pump, thank you guys for the suggestions.
I've always tried to do this when rebuilding a carb, especially on someone else's car when they were watching you do the work. When you hit the key and BAM! it starts instantly, they think you're an absolute wizard! E-Z ego booster. Also, an empty Zippo lighter fluid bottle works well to pre-fill the float bowls.
Looking at the parts diagram that screw in orfice is supposed to be the check valve so apparently that's another part of the issue. Going to order a replacement.
Another question is that the new mechanical fuel pumps for SBC are putting out 9 lbs of pressure, and the rebuild kits say 3-5 lbs for the carb. I tried using a fuel pump regulator, Mr. Gasket brand and dialed it to 4 lbs. Still getting symptoms going down the road like the carb is being overfilled and almost flooding the car out while driving or under load like getting onto the freeway. Thoughts?
Those Mr Gasket regulators are known for problems. I've had good luck with the cheap Holley regulators. Best thing to do is run a bypass regulator and a return line, keeps the pressure from creeping and keeps the fuel cooler.
Is this the one you are talking about? https://www.holley.com/products/fue...regulators/carbureted_regulators/parts/12-803
Regulators that work well will have a bypass, and a return line. Forget the new made-in-China fuel pumps, and find an older original that is rebuildable. Fuel pump kits are available, and if you need to modify the pressure, changing the diaphragm spring will do so. As for pressure? Depends on the carburetor. I run a Carter electric pump with 7 1/2 ~ 8 psi to my genuine Carter AFB's. Jon
Ford has a nice two-pole (plus ground) oil pressure switch with one terminal NC (for the oil pressure idiot light) and one terminal NO. You can use this NO terminal to control the electric choke "turn off" function, as it will only be supplying power to the choke when the engine is actually running, i.e., when oil pressure is extant. [It usually talks to the computer to let it know the engine is running.] If you are concerned about running too much current through the NO switch terminal you can trigger the choke through a relay. easy peasy https://www.autozone.com/external-e...fsGbEOVZwiIN9_V970YaAtLdEALw_wcB&gclsrc=aw.ds PRODUCT DESCRIPTION The Duralast line of vehicle electronics is designed for original equipment (OE) form, fit and function for both import and domestic vehicles. The Engine Oil Pressure Sensor/Switch reports engine oil system pressures to the on-board computer, and when oil pressure is low, will illuminate the check engine light. When not replaced, vehicle operators may not be notified of engine oil pressures falling below critical limits. In more advanced vehicles, an unreplaced faulty oil pressure switch or sensor may not notify on-board computers of critical system pressure, thus not allowing the computers to protect the engine from any damage. I hope this O/T part will help somebody solve their cold start issues on their traditional hot rod.
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