Engine Hard Starting After Days Of Rest

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Lord Sparky

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1967 440 Magnum, 600cfm Carter carburetor, electronic ignition, manual fuel pump. Engine was just tuned up with all new filters, wires, plugs, rotor, etc. Runs great once started. Battery good.

The next day after a drive, the engine starts right up with one pump of the gas pedal. Same with day two. Day three, takes a little more cranks of the starter. After that, I might have to start the engine a second time to get it going. A week later, can be much more difficult to start.

Is hard starting caused by evaporation of gas in the carburetor? Does anyone else have this issue and have some tips? More pumps of the gas pedal?
 
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Totally normal, 67 273 2bbl does the same thing.

I assume the fuel is evaporating from bowl but don't know.

We have all gotten spoiled by fuel injection
 
One way to troubleshoot the problem is to let it sit for a few days then remove the air cleaner and give it a shot or two of gas down the carb if it starts or tries to start then you know that the gas in the carb is evaporating. I had the same problem with my 318 Barracuda, I installed an inline fuel pump and it helped. Had to turn on the fuel pump a few minutes before trying to start to get the fuel into the carb.
 
Agree with above. 360/ 4bbl will start with 1 pump if driven daily. 2nd day it cranks for 5- 10 secs. By 3rd day it cranks for 20 secs, wait and crank again for 10 secs,( i figuare float bowls have to fill). It always runs great once started, with no re-start problems thru the day.
 
My truck (75F250 351M) had an Edelbrock 1406. Did the same thing. Now it has a little Street Demon 625 three barrel. It can sit for a month and pop right off with several pumps. So I don't know. It might be fuel evaporation.
 
same thing here. between the gas evaporating out of the bowls, and the fuel drain back out of the line, it takes several cranks. I intermittently crank it until it sputters to get the bowls full , then I pump it a couple times and it starts right up. I also have my choke completely removed.
 
same thing here. between the gas evaporating out of the bowls, and the fuel drain back out of the line, it takes several cranks. I intermittently crank it until it sputters to get the bowls full , then I pump it a couple times and it starts right up. I also have my choke completely removed.
Someone suggested a check valve to keep the fuel from draining back to the tank.
 
Someone suggested a check valve to keep the fuel from draining back to the tank.
But that won't stop fuel from evaporating out of carb when the car sits with a hot engine/intake. It's the hot engine and intake that boils the fuel after you shut down the engine and let it sit. The fuel bleed back is another issue.
 
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Normal.

Sometimes just crank it for 2 seconds, stop, pump the pedal 2 maybe 3 times, then restart and lightly pedal when it fires till it idles on it's own.
 
1967 440 Magnum, 600cfm Carter carburetor, electronic ignition, manual fuel pump. Engine was just tuned up with all new filters, wires, plugs, rotor, etc. Runs great once started. Battery good.

The next day after a drive, the engine starts right up with one pump of the gas pedal. Same with day two. Day three, takes a little more cranks of the starter. After that, I might have to start the engine a second time to get it going. A week later, can be much more difficult to start.

Is hard starting caused by evaporation of gas in the carburetor? Does anyone else have this issue and have some tips? More pumps of the gas pedal?
Fuel is evaporating from the carb, very common.
It's the crap fuel that we get in these modern days.
Adding a check valve wont help there is one already in your mechanical fuel pump.
Pour out a couple ounces in an open top container and see how fast it disappears. Overnight it will be gone.
No open flames and watch out for the fumes.
 
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Not the issue, my filter is less than 1 year old car does same thing.
 
it is called evaporation ...,,carter/edelbrock design suffer more with their small fuel bowl and placement of the accelerator pump well...not the bottom of the fuel bowl like a holley
 
What do you guys think about a dirty fuel filter in regards to starting?
If it was a dirty fuel filter not only would it not run well but it wouldn't start after being off for a few minutes??? If the filter is dirty it will be dirty all the time, not just after it's been off for a few days.
 
1967 440 Magnum, 600cfm Carter carburetor, electronic ignition, manual fuel pump. Engine was just tuned up with all new filters, wires, plugs, rotor, etc. Runs great once started. Battery good.

The next day after a drive, the engine starts right up with one pump of the gas pedal. Same with day two. Day three, takes a little more cranks of the starter. After that, I might have to start the engine a second time to get it going. A week later, can be much more difficult to start.

Is hard starting caused by evaporation of gas in the carburetor? Does anyone else have this issue and have some tips? More pumps of the gas pedal?

Yes fuel evaporation. Edelbrock carbs seem to be prone to that. It could be because of the float bowls being part of the carb base and absorbing a lot of engine heat. A electric priming pump, a fuel return system and carb insulators all help.

My truck (75F250 351M) had an Edelbrock 1406. Did the same thing. Now it has a little Street Demon 625 three barrel. It can sit for a month and pop right off with several pumps. So I don't know. It might be fuel evaporation.

It sees the Holley design carbs are less prone to fuel evaporation. It could be because the float bowls are isolated from the carb body and I imagine even the bowl and metering block gaskets help insulate the fuel from the heat.
 
Here's a inexpensive fix from a FBBO member. I bet it works well.

Hi Guys, I realise this is an old thread, but I thought Id let you know how I solved the fuel evaporation problem which as most of you know is the only problem Ive ever encountered with using Edelbrock Performer or the AVS800 I have on my R/T440. i presently own 3 x cars with Edelbrock carbs and this mod Ive done on 2 of them because the latest conversion I did on my 1990 Camaro from TBI to Carb didn't require priming because Im using the existing electric In-tank pump with a return regulator, so no need on that one. On both my 85 Z28 and my 67 Dodge Coronet R/T440 Ive fitted a Marine Dept approved 3/8" Mercruiser Fuel Priming Bulb fitted for easy access just prior to my Mechanical Fuel Lift Pump on both cars. Also I have fitted 0-15psi Liquid Filled pressure gauges between the Lift Pump and the Carbs. These conversions have been on the cars now since 2011 and have worked perfectly. The standard procedure I use on my cars before starting is to lift the hood, do a visual check all over for leaks anywhere, check the drive belts... and all fluid levels. Then I simply lean down and squeeze the Primer Bulb maybe 3-4 times until I see 5 psi on the gauge then I stop pumping all the while watching the gauge... if the gauge maintains that 5psi or drops to maybe 4psi, then you know the bowl(s) are full and ready. If once you stop priming the pressure on the gauge drops away you know its still not full and you can gently continue squeezing until the gauge holds steady at 5psi. Caution, yes theres always a caution... experience has taught me that simply squeezing merrily away until a positive/solid resistance is felt on the primer bulb.... will actually overpower the float needle and flood the bowl(s) these primer bulbs are very efficient at transferring liquids so a gentle touch is all thats required. In saying all the above, Ive only ever had to prime the system either if the car has been sitting for more than 1-2 days after a hot run especially during Summertime runs... or after sitting unused for an extended period like during the Winter months. Another important benefit of having such a mod is Instant Starting everytime... your Starter Motor and Battery will love you for it

990719-c153fc298a366d983bd695e4b44c95aa.png
 
Here's a inexpensive fix from a FBBO member. I bet it works well.

Hi Guys, I realise this is an old thread, but I thought Id let you know how I solved the fuel evaporation problem which as most of you know is the only problem Ive ever encountered with using Edelbrock Performer or the AVS800 I have on my R/T440. i presently own 3 x cars with Edelbrock carbs and this mod Ive done on 2 of them because the latest conversion I did on my 1990 Camaro from TBI to Carb didn't require priming because Im using the existing electric In-tank pump with a return regulator, so no need on that one. On both my 85 Z28 and my 67 Dodge Coronet R/T440 Ive fitted a Marine Dept approved 3/8" Mercruiser Fuel Priming Bulb fitted for easy access just prior to my Mechanical Fuel Lift Pump on both cars. Also I have fitted 0-15psi Liquid Filled pressure gauges between the Lift Pump and the Carbs. These conversions have been on the cars now since 2011 and have worked perfectly. The standard procedure I use on my cars before starting is to lift the hood, do a visual check all over for leaks anywhere, check the drive belts... and all fluid levels. Then I simply lean down and squeeze the Primer Bulb maybe 3-4 times until I see 5 psi on the gauge then I stop pumping all the while watching the gauge... if the gauge maintains that 5psi or drops to maybe 4psi, then you know the bowl(s) are full and ready. If once you stop priming the pressure on the gauge drops away you know its still not full and you can gently continue squeezing until the gauge holds steady at 5psi. Caution, yes theres always a caution... experience has taught me that simply squeezing merrily away until a positive/solid resistance is felt on the primer bulb.... will actually overpower the float needle and flood the bowl(s) these primer bulbs are very efficient at transferring liquids so a gentle touch is all thats required. In saying all the above, Ive only ever had to prime the system either if the car has been sitting for more than 1-2 days after a hot run especially during Summertime runs... or after sitting unused for an extended period like during the Winter months. Another important benefit of having such a mod is Instant Starting everytime... your Starter Motor and Battery will love you for it

View attachment 1715681381
That’s pretty cool. The problem seems to be solved with a new 650 AVS2.
 
That’s pretty cool. The problem seems to be solved with a new 650 AVS2.
I just happen to have one. I think I will put it on my 318 in my Swinger. LD4B and a AVS2 should be a good combination.
 
There already is a check valve in every mechanical pump.

That primer bulb needs to go on the suction side of the pump. From pump to carb should be a one-piece all metal line. Cuz if you ever have a catastrophic failure at rpm, you fuel pump can flood the underhood with gasoline which usually ends badly. Yeah I know people say to not put a filter on the suction side. And if you put a generic 5/16 on on there I would agree. But those days are long gone! Just put a big ol' hi-capacity,metal-canister, EFI filter at the back, and yur golden. Mine was new in about 1999,lol, and is still filtering just fine.
My mechanical pump is rated 80gph, so in 8 seconds say, that would be ~23 ounces. But the 80gph rating is not specified at any particular rpm. You know that a can of coke is 10 ounces right, I mean just so you can get an idea of what 23 ounces looks like covering everything under your hood. the lightest gasoline molecules vaporize at about 95*F, so if it remains a liquid under your hood, that would be a miracle.
Jus saying.
IMO, a marine primer bulb under the hood is a really bad idea.
I solved my problem with a 750DP carb. Only after a week or so do I need to prime the carb, and I have a little squirt can I use for that, I mean the guy with the primer bulb has to open his hood just like me so ....... I just splash some gas down the primaries, jump in and floor it, then hit the start button, problem solved. And no risk of fire.
I spent several years in a marine shop, and have personal experience with primer bulbs, and I sure wouldn't install one under the hood of my hotrod. They are designed to lay in the back of the boat, for a few hours, every once in a while. When you get home, the first thing you do is unplug the fuel line, and put the tank in a cool safe place, away from the sun. I mean that is why the hose has a QD on it, for heaven's sake.
But under your hood, the engine is running close to 200*F and the headers idle at double that. And the fan is pumping hot air as hard as it can. When the engine gets to working, you can read the pipes with an IR gun and see 800/900/ and perhaps 1000 degrees on them. Do you really want a rubber primer bulb full of fuel, just inches away?
I sure don't.
I park my car in the carport I built on the NORTH side of my house, out of the sun. and , I ventilated my hood, so within a few minutes of shutdown, the engine is cooling off nicely.
But to be fair, daytime temps here in Manitoba seldomly exceed 37*C or about , lessee, that would be 99*F.
 
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There already is a check valve in every mechanical pump.

That primer bulb needs to go on the suction side of the pump. From pump to carb should be a one-piece all metal line. Cuz if you ever have a catastrophic failure at rpm, you fuel pump can flood the underhood with gasoline which usually ends badly. Yeah I know people say to not put a filter on the suction side. And if you put a generic 5/16 on on there I would agree. But those days are long gone! Just put a big ol' hi-capacity,metal-canister, EFI filter at the back, and yur golden. Mine was new in about 1999,lol, and is still filtering just fine.
My mechanical pump is rated 80gph, so in 8 seconds say, that would be ~23 ounces. But the 80gph rating is not specified at any particular rpm. You know that a can of coke is 10 ounces right, I mean just so you can get an idea of what 23 ounces looks like covering everything under your hood. the lightest gasoline molecules vaporize at about 95*F, so if it remains a liquid under your hood, that would be a miracle.
Jus saying.
IMO, a marine primer bulb under the hood is a really bad idea.
I solved my problem with a 750DP carb. Only after a week or so do I need to prime the carb, and I have a little squirt can I use for that, I mean the guy with the primer bulb has to open his hood just like me so ....... I just splash some gas down the primaries, jump in and floor it, then hit the start button, problem solved. And no risk of fire.
I spent several years in a marine shop, and have personal experience with primer bulbs, and I sure wouldn't install one under the hood of my hotrod. They are designed to lay in the back of the boat, for a few hours, every once in a while. When you get home, the first thing you do is unplug the fuel line, and put the tank in a cool safe place, away from the sun. I mean that is why the hose has a QD on it, for heaven's sake.
But under your hood, the engine is running close to 200*F and the headers idle at double that. And the fan is pumping hot air as hard as it can. When the engine gets to working, you can read the pipes with an IR gun and see 800/900/ and perhaps 1000 degrees on them. Do you really want a rubber primer bulb full of fuel, just inches away?
I sure don't.
I park my car in the carport I built on the NORTH side of my house, out of the sun. and , I ventilated my hood, so within a few minutes of shutdown, the engine is cooling off nicely.
But to be fair, daytime temps here in Manitoba seldomly exceed 37*C or about , lessee, that would be 99*F.
The op from FBBO put the primer on the suction side of the pump if I read right. It could be dangerous but so is a electric pump that is hooked to a toggle switch and not the oil pressure switch or a rollover valve. Just sayin.
 
yeah Mike you got it right.
But the primer pump can be at the back and on a momentary on button; push and hold to pump. Release to stop.
putting the primer bulb on the suction side, under the hood, comes with it's own set of bonehead ideas, cuz the headers are even closer.

To help combat heat, when I fabricated my 3/8 steel line, I put it into the front stub frame, and brought it out very near to the pump. My steel line terminates within inches of the pump. I drilled a large enough exit hole in the frame to allow for engine movement, and did not secure the fuel line inside the frame. I hand formed the edges of the hole so as not to cut the fuel-line. Then after the engine was installed, I tied her down with a torque-strap. The jumper hose is less than 4 inches long, as the supply line is nearly touching the pump inlet. That was year 2000IIRC
 
yeah Mike you got it right.
But the primer pump can be at the back and on a momentary on button; push and hold to pump. Release to stop.
putting the primer bulb on the suction side, under the hood, comes with it's own set of bonehead ideas, cuz the headers are even closer.

To help combat heat, when I fabricated my 3/8 steel line, I put it into the front stub frame, and brought it out very near to the pump. My steel line terminates within inches of the pump. I drilled a large enough exit hole in the frame to allow for engine movement, and did not secure the fuel line inside the frame. I hand formed the edges of the hole so as not to cut the fuel-line. Then after the engine was installed, I tied her down with a torque-strap. The jumper hose is less than 4 inches long, as the supply line is nearly touching the pump inlet. That was year 2000IIRC
I agree, heat and a rubber primer bulb are a bad combination. Yes, if you have a electric priming pump it needs to be on a momentary push button switch. Should have elaborated. How many cars ave electric pumps simply hooked up to a toggle switch. Oh boy, could that be dangerous in so many situations as well.
 
That's how carbureted vehicles work. They ain't EFI.
 
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