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Old 10-29-2010, 11:41 AM   #1
exploderjim
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Hard starting

I was wondering if there is a fix or suggestion for the fuel draining back out of the fuel line after it sits for a while? If the truck is started and run then restarted no issue but once it sits for a while the clear fuel filter is dry and the engine turns over until the fuel gets back up to the carb. Any thoughts such as a check valve or something?
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Old 10-29-2010, 02:59 PM   #2
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Re: Hard starting

Mine does the same thing, I always just push the accelerator to the floor and then turn the key. Usually starts up but not always.
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Old 10-29-2010, 03:33 PM   #3
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Re: Hard starting

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Originally Posted by exploderjim View Post
I was wondering if there is a fix or suggestion for the fuel draining back out of the fuel line after it sits for a while? If the truck is started and run then restarted no issue but once it sits for a while the clear fuel filter is dry and the engine turns over until the fuel gets back up to the carb. Any thoughts such as a check valve or something?
Sounds like some of the gaskets in your carb are old and are letting the fuel bleed back off. Might want to consider rebuilding your carb with new gaskets and what not. Should correct the bleed off problem. I know when mine sits, the fuel almost never runs back down out of the filter. If its not that, I guess it could be the fuel pump having the same problem. Once the fuel gets to the pump, you usually have to crimp a line to get it to stop coming out when changing them.
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Old 10-29-2010, 04:04 PM   #4
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Re: Hard starting

Actually the carb is a brand new Edelbrock. If you pump the gas when it is starting it will fire and run perfectly. if you shut it off and retry anytime until its cold it will fire immediately. There is a new engine driven pump as well. Is it possible to put in a check valve of some sort to prevent the bleeding done or any other ideas?

Last edited by exploderjim; 10-29-2010 at 04:05 PM.
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Old 10-29-2010, 04:20 PM   #5
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Re: Hard starting

its common problem with edelbrock carbs used without phenolic spacers to isolate the carb from heat transfer//i believe it is in the instruction book that comes with the carb
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Old 10-29-2010, 04:22 PM   #6
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Re: Hard starting

There should be enough fuel in the bowls to start it up. I pump the gas pedal once when the motors cold and it's good to go. Edelbrock carb here as well.
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Old 10-30-2010, 11:02 AM   #7
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Re: Hard starting

I have a spacer already in place. I just hate having to crank the motor over until the fuel is pumped back to the carb. There is fuel still in the carb as it lights then quits until the fresh supply reaches the carb again. I know i'm saying to over again but it's like it syphons back to the tank some how.
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Old 10-30-2010, 11:23 AM   #8
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Re: Hard starting

There is a check valve system in the fuel pump to keep this from happening and when they get old they don't hold. The gravity pressure of the fuel will allow it to run back through the fuel pump. It does this on every hot rod I have when I don't drive them for awhile.

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Old 10-30-2010, 05:02 PM   #9
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Re: Hard starting

It's a brand new fuel pump. Maybe it has a defective check valve. When it had the old stock carb and fuel pump it didn't do this. I thought I was doing the right thing putting in a new edelbrock and fuel pump. Seems it's turned into a pain in the a....
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Old 10-30-2010, 05:14 PM   #10
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Re: Hard starting

when you replaced the fuel pump did you use a good rigid tubing one one did you go with the exploder rubber lines that lay on the hot manifold
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Old 10-30-2010, 06:29 PM   #11
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Re: Hard starting

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Originally Posted by exploderjim View Post
I thought I was doing the right thing putting in a new edelbrock and fuel pump. Seems it's turned into a pain in the a....
Well.....actually doing the right thing is 6 little letters known as "HOLLEY" but it's a mistake a lot of people make. LOL
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Old 10-30-2010, 08:29 PM   #12
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Re: Hard starting

I'm running an Edelbrock with a 1" phenolic spacer. This eliminated the hard hot start. It sounds like your problem is with your fuel pump.
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Old 10-30-2010, 11:35 PM   #13
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Re: Hard starting

Just to clear this up a bit when the truck is hot it all works perfectly. The problem is when its cold if you check the glass fuel filter it is empty. When I turn it over it fires for a second using the fuel in the carb then turns over until the fuel makes it back through the filter and into the carb. As time goes by or the engine cools the fuel is syphoning back out of the fuel line and out of the glass fuel filter. I thought maybe there was a fuel filter that had a check valve to prevent the back flow of fuel or maybe the engine driven pump was letting the fuel drain back through it. I drove the truck from Seattle to Buffalo last winter and blew the fuel pump in Chicago. The garage put one on from autozone. So I thought that might be the issue. Thanks to all who are giving me advice I appreciate it.
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Old 10-30-2010, 11:36 PM   #14
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Re: Hard starting

not sure if it matters but the engine is a 402
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Old 10-31-2010, 09:32 AM   #15
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Re: Hard starting

Fuel pump I got from autozone couldn't keep up, switched to ACDELCO problem solved. With holly, it will bump idle from a cold start but sometimes depending on how many days it sits, I have to slightly press after start to keep her running. The fuel filter thing didn't make any difference ever, but the holly seems to retain enough fuel to run. I raised my float bowls, it not for the cam it would idle perfectly from a dead cold start.

Last edited by aintmisbehavinn; 10-31-2010 at 09:33 AM.
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Old 10-31-2010, 09:39 AM   #16
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Re: Hard starting

Sounds like my best bet is to replace the fuel pump with a quality AC Delco unit otherwise live with the issue of cranking for 5-10 secs for it to start cold. Like I said once running it will start first touch of the key. I think you guys have givin me some good insight thanks.
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