Guys, why am I pumping and cranking?

[Nevada dan]

I got tired of adjusting the choke , we have suck temperature changes here that every month you have to move the choke setting, so I put a manual choke on, I pump the gas once while setting the choke , crank for 5 seconds then pump twice crank again and she fires right up , feather the choke off and go, I know everyone wants thing to be automatic now days but this has always worked best for me, I learned how to drive in 40's and 50's vehicles so it's normal to me

 

[toolmanmike]

If it takes 30 seconds or more to get fuel to the carb it is probably due to a problem with the pump. Either bad check valve or pump diaphragm allowing it to drain back.

I had this problem before adding a fuel pressure regulator. Many seconds of cranking before firing if it had been sitting even a couple days. Added a fuel pressure regulator in the engine compartment and it fires right off, even after a week or more of sitting, but runs like garbage for 10-15 seconds. The regulator keeps enough fuel available to fire off, but not enough to run well while the pump is trying to do its thing.

It’s not an evaporation problem, at least in my case. I’m replacing the pump this week, I’m sure it’s the issue.

Let us know. I have 2 cars that do the same thing. One has a 10 year old pump and the other has a 30+ year old pump. I have a squirt bottle of gas that I squirt down the bowl vents to fill the float bowls. That works but it is quite inconvenient. The Edelbrock on my 273 is much more prone to it than the BBD on my 318. After a drive I can actually hear the fuel percolating in the Edelbrock. I need a insulator there.. It would be interesting to put a manual fuel shut off to make sure the fuel wasn't draining back. Good luck and let us know.

 

[toolmanmike]

Here's a pump a lot are using. Wire it up with a momentary switch. You need a rotary pump so the fuel flows through it easily when the pump is off. https://www.summitracing.com/parts/atx-e8012s

 

[Ranger16]

After my 383 with an Edelbrock 1411 sits for several days I prime the float bowls via the vents with a plastic bottle full of gas. Greatly shortens crank times.

 

[WileE]

After my 383 with an Edelbrock 1411 sits for several days I prime the float bowls via the vents with a plastic bottle full of gas. Greatly shortens crank times.

View attachment 1131601

^^^ This ^^^ Hit the nail on the head. Let's not get into a whole rigamarole of stuff to do. It's simple, it's the gasoline. My stock 318 fires up instantly after a few days, gets this ^^ squirt bottle treatment when the car has sat for a week or so. ( Disclaimer: my squirt bottle is red, I don't use ketchup )

 

[tonysrt]

Open the hood remove the air cleaner and squirt gas in carb. Start car put air cleaner back on and close hood. Too many things to do when electric pump solves problem. Also storing gas in a plastic bottle not such a good idea.

 

[R413]

Too many things to do? How do you get out of bed and face the day?

storing gas in a plastic bottle? What 4-6 ounces is a danger?

 

[furyus]

I also have an electric fuel pump with a momentary switch. Push button, fills fuel bowl, 2 pumps, and hit the key.

 

[MarPar]

There's a joke somewhere in the title of this thread, but I am not touching that one.

 

[Fran Blacker]

Put this inline, not my idea but was posted a few years ago. I would keep an eye on it for cracking.

 

[Dashman]

Hello everyone, long time reader but not much of a poster. Great ideas, they will all probably work for one application or another. As posted, it's a heat soak problem and once in a while it will even happen to our shop car if occasionally using a lower grade fuel if the station didn't have a better grade.

Top three issues we discuss weekly, #1 a phenolic insulator is a must, #2 the heat crossover must be blocked off, #3 use the best fuel you can either get or afford like 91 or better. I'll even add a fourth, check your fuel pressure to make sure that doesn't add an extra headache for you, that will give you host of problems as well.

Adding a quick fix of pumping fuel electrically or dumping it in mechanically by hand works. But we have to stop and think where all that fuel eventually ends up going? Ever smell gas in your oil? What is that going to do to your investment down the line? Try to solve the problem the right way if possible, EFI is out of reach for a lot of guys or they simply like a reliable tuned carburetor that is set up for todays fuel.

Dashman's Hot Rod & Speed Parts

 

[toolmanmike]

Hello everyone, long time reader but not much of a poster. Great ideas, they will all probably work for one application or another. As posted, it's a heat soak problem and once in a while it will even happen to our shop car if occasionally using a lower grade fuel if the station didn't have a better grade.

Top three issues we discuss weekly, #1 a phenolic insulator is a must, #2 the heat crossover must be blocked off, #3 use the best fuel you can either get or afford like 91 or better. I'll even add a fourth, check your fuel pressure to make sure that doesn't add an extra headache for you, that will give you host of problems as well.

Adding a quick fix of pumping fuel electrically or dumping it in mechanically by hand works. But we have to stop and think where all that fuel eventually ends up going? Ever smell gas in your oil? What is that going to do to your investment down the line? Try to solve the problem the right way if possible, EFI is out of reach for a lot of guys or they simply like a reliable tuned carburetor that is set up for todays fuel.

Dashman's Hot Rod & Speed Parts

Yes, yes and yes. The electric charge pumps won't force fuel down the carb and into the crankcase though. As long as the pressure isn't too high and the needle/seat and float are all operating properly, the fuel will be shut off when the bowl is full.

 

[dadeo]

You know I have the same symptoms on my six pack Challenger and I know it's not heat soak. I can start the car cold, only let it run for a few minutes and shut it off and 4 days later I'm a cranking madman. Leaving a glass of gas on the garage shelf marking its height and no drop after 4 days. So that much evaporation is doubtful. Everything is pointing to the vapor separator - orifice (.06" I believe) size and tube lengths in the separator. Not to spec vapor separators sold is where I'm leaning. I'm going to buy a new one and cut the old one in half to see if it's to spec.
Andy

 

[Dashman]

Very true. My question should have been more to the point, "what happens to all the boiled fuel that evaporates over and over again?" The answer is probably heading south to the crankcase where you don't want it or all over your intake manifold where a fire could start. We have seen both scenarios, it just isn't going to get any better if the problem isn't solved. The solutions are posted, take care everyone.

 

[tonysrt]

Since fuel is evaporating it actually becomes a gas and rises. The fuel is contained in the bowl and as it is heated may make its way into, if it can get by the needle of the float, into primary venturi. Don't think it'll be in crankcase, unless a lot of fluid is passed and then thru open valves off intake manifold. I've used phenolic spacers that limit the heat soak condition. Some carbs are worse causing this condition.

 

[funknut]

If it takes 30 seconds or more to get fuel to the carb it is probably due to a problem with the pump. Either bad check valve or pump diaphragm allowing it to drain back.

I had this problem before adding a fuel pressure regulator. Many seconds of cranking before firing if it had been sitting even a couple days. Added a fuel pressure regulator in the engine compartment and it fires right off, even after a week or more of sitting, but runs like garbage for 10-15 seconds. The regulator keeps enough fuel available to fire off, but not enough to run well while the pump is trying to do its thing.

It’s not an evaporation problem, at least in my case. I’m replacing the pump this week, I’m sure it’s the issue.

Took longer than I expected, but I have had the new pump in for the last week and a half and the drainback issue is hugely improved. It doesn't kick over on the first crank when warm or when it's been sitting, so I'm sure there's some evaporation happening, but I no longer have the 20+ seconds of cranking after it's been sitting a day or more. I plan to take apart the old pump to see if I can figure out what the issue was, but so far the new pump has made a huge difference in my case.

 

[RJRENTON]

Hello all: I have a very stock 69 Charger RT/SE with a stock 440 HP motor running the stock Carter AVS 4640S carb, which has been rebuilt. Stock fuel pump, lines and vapor separator. The engine runs well. When the car has sat for more than 3-4 days, I have to crank it a lot ( 30 - 40 sec.) to get it started. The carb accelerator pump and choke are working correctly. But when I start it up after sitting for only a day, it fires right up. It's as if all the fuel drained out of the carb and fuel lines from the fuel pump, and it takes forever for the fuel to make its way back to the engine. It has to sit for about four days, as I mentioned, for this problem to appear. Also, the engine does not go to a high idle after starting. Just a normal curb idle. Are these things supposed to go to a high idle that you kick down before you begin driving? Ideas? Thanks.

IMO....
The Carter AVS 4640S carb is not prone to fuel evaporation issues, in spite of today's ethanol blended gasoline, once the float levels are at specs. As far as the no fast idle condition, when the choke closes, the fast idle cam (located on the throttle linkage side of the carb), is lifted up, by a link connected to the choke shaft. Is the link in place? Is the the choke shaft stuck? Is the fast idle cam cam free and able to move? Is the choke pull off diaphragm to choke shaft link adjusted to the correct dimension? Is the choke pull off diaphragm assembly functional? The FSM provides these dimensions as well as the procedures to make the adjustments.
However, there are several pressed in place sealing plugs (used to seal drilled passageways) only visable from the bottom side of the carb, that MAY BE LEAKING. Four of these plugged passages are directly under the main metering jets. Two additional passageways are part of the accelerator pump system which, if leaking, could cause the fuel bowls to empty over time, requiring long cranking times to restart.
The Carter AVS is a reliable carb but not without a few issues....mostly dealing with emission control requirements but these "problems" can be easily overcome with minor changes to the metering rods and jets.
Just my opinion of course.
BOB RENTON