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Discussion Starter #1
So my car is having this new problem this year where after it sits for a while (week?) it takes forever to start the next time. I have to sit there and turn it over for 5 minutes before it’ll start. It’s pretty much as if it’s not getting any fuel and then all the sudden it is. After it’s started though, it runs great and I can drive it all over town. And if I shut it off, it’ll start back up again no problem. I suspect it’s a carb issue, the carb is a Holley Street Avenger 570 with electric choke. It’s not a choke issue, we’ve already addressed that. Like I said, it’s almost as if it’s starved for fuel. I don’t think it’s a fuel pump issue, I have an old school USA made Holley electric blue pump and my fuel gauge has plenty of pressure. I don’t know enough about the specifics in a carb to narrow down the issue, just enough to be dangerous. It’s almost as if the fuel bowls go dry while it sits. I’m at a loss because I don’t know what else to do to diagnose the problem.
 

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Fuel or spark. If you have points, check the gap.
When you installed the Avenger did you do any adjusting to it, or run it as is?
 

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I hate to state the obvious but you do know you have to pump the accelerator 4,5 times before starting especially after it has set up, if mine has set up a week or two I’ll pump accelerator wait a few seconds and pump again then fire right up.
 

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After sitting for a week the fuel has evaporated from the fuel bowl. You have an electric pump so let it run long enough to refill the bowl before attempting to start. Then as stated, pump the accelerator pedal however many times are needed to get some gas in the engine.
 

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Discussion Starter #5
Fuel or spark. If you have points, check the gap.
When you installed the Avenger did you do any adjusting to it, or run it as is?
It’s been adjusted a lot in the past 12 years.

Also, in reply to others, of course I know to pump it several times. And I’ve let the fuel pump run for 5 minutes before attempting to start it and it still does it. It’s none of those things.
 

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After a minute or two of cranking before it actually starts go do a tailpipe sniff. You may be flooding it either by too many pumps or a borderline float valve. If everything works as you say, you should be able to hit the fuel pump, listen till it labors meaning the bowl is full, hit two full pumps it should start.

Try running your fuel pump till it fills the carb then turn it off till the car actually starts. Now try two pumps and see if it starts. It may be a float sticking that is worked free by the vibration of the motor running.

I would also pull the air cleaner with the motor cold and turn on the pump while looking down the carb with a flashlight. See if its leaking/pouring fuel into the intake.

BTW, while to anyone with carbs knows you pump the throttle, these daze, with fuel injection, its not a given that people know to pump the fuel - I was about to write the same thing...

That's all I got - good luck
 

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Discussion Starter #7
It’s not flooding it, that much we’ve checked. I’m no rookie when it comes to motors, I built this one myself and it has been faithful for 12 years. I suspect, as you said, that something is sticking within the carb, whether it be the float not letting the fuel bowl fill up or maybe the accelerator pump. I just don’t know how to narrow it down. I’ve thought about rebuilding the carb but I’d hate to go that drastic because as I said, the thing runs great after I eventually do get it started. And like sitting overnight is no problem, I went and fired it up this morning with no issue.
 

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Should be pretty basic for someone that isn't a rookie. Just let the fuel pump run pull the air cleaner off and check to see if moving the throttle sprays fuel down the throat. If not you have no fuel in the bowl. Problem solved. Stuck needle possibly. I would hardly call a carb rebuild drastic. You should be able to have it off, cleaned and back on in a couple hours tops.
 

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Should be pretty basic for someone that isn't a rookie. Just let the fuel pump run pull the air cleaner off and check to see if moving the throttle sprays fuel down the throat. If not you have no fuel in the bowl. Problem solved. Stuck needle possibly. I would hardly call a carb rebuild drastic. You should be able to have it off, cleaned and back on in a couple hours tops.
Okay, now we may be on to something. If it’s a stuck needle, what would that cause?

Also, jdub, I’m just trying to explain what we’ve already ruled out. And hopefully you could see how it would be a little insulting if you presented a problem and someone told you that you weren’t pumping the gas pedal. Give my intelligence a little credit.
 

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Okay, now we may be on to something. If it’s a stuck needle, what would that cause?

Also, jdub, I’m just trying to explain what we’ve already ruled out. And hopefully you could see how it would be a little insulting if you presented a problem and someone told you that you weren’t pumping the gas pedal. Give my intelligence a little credit.
Don't get too insulted, it's a very common issue if you haven't been around carbureted cars, which haven't been made in 30 years, sometimes even if you have. Also, don't take this the wrong way but if you don't understand what a stuck needle in a carburetor would cause then your knowledge is very limited or you were in the bathroom when they covered that in mechanics class.
Check out this video from years gone by that deals with this very issue that someone recently posted. If you watch the video you can see in the diagram the fuel bowl with float and needle and you can see if the needle doesn't open and it stays stuck no fuel will be in the bowl and therefore you could pump until the cows come home or until the needle unsticks. By the way I'm not saying this is your problem but you should at least rule it out.
For the carbureted folks, vintage video on correct...
 

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12 years of winter storage and ethanol blended fuel plays havoc over time. I would pull the carb, take it apart and give all the ports a good cleaning.
 

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To try to figure out of the gas is leaking down into the intake or evaporating, check your oil (maybe to safe, just do an oil change).

If it's leaking into the intake and slipping down into one of the open intake valves, could be leaking by the rings and getting down into the oil pan. You don't want the oil thinning out too much or you'll be damaging the motor.
 

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Also, jdub, I’m just trying to explain what we’ve already ruled out. And hopefully you could see how it would be a little insulting if you presented a problem and someone told you that you weren’t pumping the gas pedal. Give my intelligence a little credit.
See the thread in this forum heading where the guy asks what wires to connect his electric fan to. Never know what experience you're working with on the internet these days. When I read your post the pedal pump was the first thing I thought of too. Sorry, not an insult, we just gravitate toward the easy fix.

I actually had the same problem as you. I could kill the battery just sitting their cranking it but ran fine once started and hot starts were fine as long as the correct hot start procedure (no pumps, hold 1/4 throttle) was followed. I was told by members here to dump about a shot glass of gasoline down the carb. This worked instantly, every time. I pulled that engine and replaced it in its entirety so I never isolated the exact problem but it was definitely a fuel issue after the car had sat, that then went away once running. I had a mechanical pump though, which I suspected to be the issue, so with your electric pump it's a bit of curiousity to me. But this simple trick (dumping about an oz of fuel down the carb), if you haven't already done it, may tell you a lot.
 

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Discussion Starter #15
See the thread in this forum heading where the guy asks what wires to connect his electric fan to. Never know what experience you're working with on the internet these days. When I read your post the pedal pump was the first thing I thought of too. Sorry, not an insult, we just gravitate toward the easy fix.

I actually had the same problem as you. I could kill the battery just sitting their cranking it but ran fine once started and hot starts were fine as long as the correct hot start procedure (no pumps, hold 1/4 throttle) was followed. I was told by members here to dump about a shot glass of gasoline down the carb. This worked instantly, every time. I pulled that engine and replaced it in its entirety so I never isolated the exact problem but it was definitely a fuel issue after the car had sat, that then went away once running. I had a mechanical pump though, which I suspected to be the issue, so with your electric pump it's a bit of curiousity to me. But this simple trick (dumping about an oz of fuel down the carb), if you haven't already done it, may tell you a lot.
That’s my plan for the next time I go to start it. I’m hoping not to have to rebuild the carb on this because I’ve seen the instruction manual Holley provides with the kit and it’s complete garbage, almost no help at all.
 

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That’s my plan for the next time I go to start it. I’m hoping not to have to rebuild the carb on this because I’ve seen the instruction manual Holley provides with the kit and it’s complete garbage, almost no help at all.
As David Robinson said, first pull off the air cleaner and make sure it is getting a pump shot. If it is not, then take out the float level screw (or look through the window) and bump the fender to rock the car to make sure the float level is correct. If float level is correct and you get no pump shot then the accelerator pump diaphragm is likely bad or pump nozzles are clogged.

It is not hard to re-build. It is largely disassembly, cleaning and re-assembly with new gaskets. Taking a few pictures along the way can be helpful. The kits usually service a wide range of carb models so they give you way more gaskets than are appropriate for your specific carb. It's not that hard to sort through to find ones that look like what you removed. You will also need a razor blade or sharp scraper to remove gaskets that are stuck. At a minimum I would recommend pulling the float bowls off to see what crap might be in them and to insure that the float needles move freely.
 

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So my car is having this new problem this year where after it sits for a while (week?) it takes forever to start the next time. I have to sit there and turn it over for 5 minutes before it’ll start. It’s pretty much as if it’s not getting any fuel and then all the sudden it is. After it’s started though, it runs great and I can drive it all over town. And if I shut it off, it’ll start back up again no problem. I suspect it’s a carb issue, the carb is a Holley Street Avenger 570 with electric choke. It’s not a choke issue, we’ve already addressed that. Like I said, it’s almost as if it’s starved for fuel. I don’t think it’s a fuel pump issue, I have an old school USA made Holley electric blue pump and my fuel gauge has plenty of pressure. I don’t know enough about the specifics in a carb to narrow down the issue, just enough to be dangerous. It’s almost as if the fuel bowls go dry while it sits. I’m at a loss because I don’t know what else to do to diagnose the problem.
Totally normal for today's gasoline. The carb bowls are dry and the fuel pump must fill them to start. Usually a couple of revolutions with the starter and a couple of good pumps on the skinny pedal will bring a week old Mustang to life.

I just re-read you post and you have a electric pump. If it turns on with the key, turn the key to run, wait a few seconds for the carb to fill, smash the skinny pedal and crank. Should fire in .5 seconds.
 

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If it weren't for the electric pump in the mix I'd say it was regular fuel drainback and evaporation problems. I have to wonder how the fuel pump is wired in. I've seen some wired in through an oil pressure switch for safety reasons. The idea being if there was a crash or something where the engine quit running then the fuel pump would be cut off automatically too. More of a race car thing but I can picture it wired that way so that the fuel pump would not be allowed to come until the engine developed oil pressure. So it would indeed take a while cold. With a warm engine there'd be plenty of fuel in the bowls so if the pump lagged a little it wouldn't be noticeable.

Just spitballing. Most retrofitted fuel pumps aren't hooked up in such complicated ways. I had a modified MG once that had a diaphragm pump in the trunk area. Starting procedure for it was to turn the key on and listen to the pump.It went "bapbapbapbap bap bap bap ....bap......bap..........bap" and then you cranked the engine up. Pretty how I like to do mine though I don't use pumps that make such obvious noises these days. For safety purposes I use inertia switches because I don't care for the oil pressure style setup. Just my preference though.
 

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Discussion Starter #19
If it weren't for the electric pump in the mix I'd say it was regular fuel drainback and evaporation problems. I have to wonder how the fuel pump is wired in. I've seen some wired in through an oil pressure switch for safety reasons. The idea being if there was a crash or something where the engine quit running then the fuel pump would be cut off automatically too. More of a race car thing but I can picture it wired that way so that the fuel pump would not be allowed to come until the engine developed oil pressure. So it would indeed take a while cold. With a warm engine there'd be plenty of fuel in the bowls so if the pump lagged a little it wouldn't be noticeable.

Just spitballing. Most retrofitted fuel pumps aren't hooked up in such complicated ways. I had a modified MG once that had a diaphragm pump in the trunk area. Starting procedure for it was to turn the key on and listen to the pump.It went "bapbapbapbap bap bap bap ....bap......bap..........bap" and then you cranked the engine up. Pretty how I like to do mine though I don't use pumps that make such obvious noises these days. For safety purposes I use inertia switches because I don't care for the oil pressure style setup. Just my preference though.
It’s wired to be on all the time when the key is on via a relay to the ignition. Nothing fancy.
 

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So you've tried just turning the key to "ignition on" a minute or two to "prime" it before actually cranking the engine?
 
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