Hard starting when cold, no fuel in filter
May 2nd, 2012, 04:26 PM
#1
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Join Date: Mar 2012
Posts: 4
Hard starting when cold, no fuel in filter
I have a '69 442, original engine w/Edlebrock carb and stock fuel pump. Starts easy, runs well after being warmed up.
Starting cold, say after sitting for a few days, takes a lot of cranking.
I'm not sure if the problem is spark, fuel, or something else.
The fuel filter is the glass type, and I cannot see any fuel in it when it's been sitting for a few days or a week. I can see fuel in the filter when the engine is running. I cannot smell any fuel, or see any signs of a leak.
Do I have a fuel problem? Is the fuel running back down/out thru the pump and back to tank? Could this indicate an air leak or a bad pump?
Thanks,
Skyko
Starting cold, say after sitting for a few days, takes a lot of cranking.
I'm not sure if the problem is spark, fuel, or something else.
The fuel filter is the glass type, and I cannot see any fuel in it when it's been sitting for a few days or a week. I can see fuel in the filter when the engine is running. I cannot smell any fuel, or see any signs of a leak.
Do I have a fuel problem? Is the fuel running back down/out thru the pump and back to tank? Could this indicate an air leak or a bad pump?
Thanks,
Skyko
May 3rd, 2012, 06:19 AM
#2
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Join Date: Oct 2007
Posts: 91
I'll be watching this thread also.
Almost every car I have ever had that has a carb on it is hard to start after more than 24 hours of sitting.
My 72 now, I just get in bump the throttle one time and turn the key until it starts. It takes about 15-25 seconds so I just grind until it starts. If I drive it after say 5 in the afternoon and then start it the next morning, it starts within 10 seconds.
I have checked everything about the carb. I have not changed the fuel pump to see if that is the difference.
Almost every car I have ever had that has a carb on it is hard to start after more than 24 hours of sitting.
My 72 now, I just get in bump the throttle one time and turn the key until it starts. It takes about 15-25 seconds so I just grind until it starts. If I drive it after say 5 in the afternoon and then start it the next morning, it starts within 10 seconds.
I have checked everything about the carb. I have not changed the fuel pump to see if that is the difference.
May 4th, 2012, 06:42 PM
#3
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Join Date: Aug 2009
Posts: 333
Does the fuel filter have the little pressure valve in it? I've been having the same issue, noticed that the valve was not present and replaced the filter with one that did - but then I dropped the car off to have the rear quarter welded before I had time to notice if it made a difference or not...
May 4th, 2012, 07:43 PM
#4
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Join Date: Apr 2011
Posts: 2,703
First thing is first...the glass filters are junk. While they look cool, most of the time they loosen and you will end up with a fuel leak...even if you don't smell the gas. With the car running, run your finger along the bottom of the filter from end to end, if it feels slimy then there's a leak. Disconnect both ends and tighten the filter up...or get rid of it and install a good one piece aluminum filter.
Second, the sure sign of a bad pump diaphragm is that it doesn't hold fuel to the carburetor side of the pump once it is shut off. If $35 isn't a big deal to you, then it is worth getting a new pump from the parts store and replacing it.
Starting a carbureted engine doesn't have to be a nightmare, but the components have to be in good working order. The delay in starting isn't the carburetor, it's the mechanical fuel pump itself. The engine has to turn over for the pump to push fuel to the carburetor. Once the fuel pump pressurizes the fuel bowl, the idle circuits get fuel and the motor can start. A way to cheat that process is just as suggested above, apply some throttle (force gas into the intake) and then crank. The initial fuel will ignite and once the engine is turning the fuel pump will play catch up.
A way around all of this (which I finally did to my car) is to install an electric fuel pump. With the key in the "on" position, the electric pump pushes 7 psi fuel pressure into the carburetor before you even turn the engine over. Once you do, a tuned carburetor will light off immediately. I have a tuned Holley HP 950 with no choke at all and my car now starts on the first bump of the starter every time, cold or hot.
Steve
Second, the sure sign of a bad pump diaphragm is that it doesn't hold fuel to the carburetor side of the pump once it is shut off. If $35 isn't a big deal to you, then it is worth getting a new pump from the parts store and replacing it.
Starting a carbureted engine doesn't have to be a nightmare, but the components have to be in good working order. The delay in starting isn't the carburetor, it's the mechanical fuel pump itself. The engine has to turn over for the pump to push fuel to the carburetor. Once the fuel pump pressurizes the fuel bowl, the idle circuits get fuel and the motor can start. A way to cheat that process is just as suggested above, apply some throttle (force gas into the intake) and then crank. The initial fuel will ignite and once the engine is turning the fuel pump will play catch up.
A way around all of this (which I finally did to my car) is to install an electric fuel pump. With the key in the "on" position, the electric pump pushes 7 psi fuel pressure into the carburetor before you even turn the engine over. Once you do, a tuned carburetor will light off immediately. I have a tuned Holley HP 950 with no choke at all and my car now starts on the first bump of the starter every time, cold or hot.
Steve
May 8th, 2012, 04:13 PM
#5
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Join Date: Mar 2012
Posts: 4
Wrong fuel pump, diconnected/plugged return line
Problem not yet resolved, but some progress:
I was looking over the fuel pump and realized I may have the wrong type. My car is a numbers-matching '69 442 w/AC. It should have the three-line fuel pump, from what I've read here.
My car has the two-line pump.
I started looking and found the return fuel line, disconnected, and plugged with a bolt and hose clamp.
Is it possible that there's enough of a vacuum in the tank with this line plugged to cause it to slowly draw fuel back out of the pump and filter?
I've ordered a new three-line pump. Once installed I'll blow out the return line and connect to the pump.
I'll replace the fuel filter and update with results.
I was looking over the fuel pump and realized I may have the wrong type. My car is a numbers-matching '69 442 w/AC. It should have the three-line fuel pump, from what I've read here.
My car has the two-line pump.
I started looking and found the return fuel line, disconnected, and plugged with a bolt and hose clamp.
Is it possible that there's enough of a vacuum in the tank with this line plugged to cause it to slowly draw fuel back out of the pump and filter?
I've ordered a new three-line pump. Once installed I'll blow out the return line and connect to the pump.
I'll replace the fuel filter and update with results.
Last edited by Skyko; May 8th, 2012 at 04:16 PM.
May 8th, 2012, 04:18 PM
#6
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Join Date: Oct 2009
Location: Poteau, Ok
Posts: 40,519
I don't think that is your problem. I would make sure your choke is operating correctly. Even though the fuel filter might have drained back, you still have a full bowl of fuel in the carb. Normally 1-2 full pumps on the fun peday will set the choke and prime the manifold.
Also make sure your tune is good.
Also make sure your tune is good.
May 9th, 2012, 05:10 AM
#8
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Join Date: Nov 2006
Location: SE Wisconsin
Posts: 1,915
I suspect the problem you have is one that many/most of us face. It is that the composition of ethanol is that it evaporates far quicker than "good old fashion" gasoline. In lieu of an electric fuel pump, simply use a squeeze bottle of some type to fill the carb fuel bowl through the fuel bowl vent tube(s). Then give the accelerator pedal a tap to set the choke, and one pump to feed some gas and she will take right off.
May 9th, 2012, 05:58 AM
#9
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Join Date: Oct 2007
Posts: 91
I suspect the problem you have is one that many/most of us face. It is that the composition of ethanol is that it evaporates far quicker than "good old fashion" gasoline. In lieu of an electric fuel pump, simply use a squeeze bottle of some type to fill the carb fuel bowl through the fuel bowl vent tube(s). Then give the accelerator pedal a tap to set the choke, and one pump to feed some gas and she will take right off.
May 9th, 2012, 06:15 AM
#10
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Join Date: Jun 2010
Location: Rogues Island, USA
Posts: 3,613
Simple question: Are you setting the choke at each cold start by depressing the gas pedal?
I see it's been brought up but many 'new guys' may not be aware of this simple step on an engine with a carb. I know many of you have not grown up in the 50s, 60s or 70s
I see it's been brought up but many 'new guys' may not be aware of this simple step on an engine with a carb. I know many of you have not grown up in the 50s, 60s or 70s
May 9th, 2012, 07:04 AM
#11
Connoisseur d'Junque
Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
The owner's manual gives clear instructions for what to do the start the car:
Generally, if it's cold press once to the floor and then crank, if it's very cold pump a couple of times, if it's hot, crack the throttle a little bit.
People don't read the starting instructions (the instructions for my diesel truck say depress pedal halfway for cold starts to freezing, all the way for cold starts below freezing), and then they wonder why their car won't start.
- Eric
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