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Discussion Starter #1
Hey guys I need your help on this.after about 10 to 15 minutes of drive time my 69 390 dies on me.when I pop the hood the clear gas filter is empty.if I crack it open slightly it sounds like you've just opened a bottle of pop under pressure and the gas comes rushing back into it.I've replaced everything from the gas cap to the carb and still no luck.But after I replace the fuel pump it runs great in all different temperatures for about 2 weeks then I'm back to square one again.right now it has a Holley high volume high pressure fuel pump as well as a 780 carb but it's still the same,has anyone run into this before?what the heck am I missing,I've been at this for a year now and I would really like to drive it for more then 10 minutes at a time.any help is always welcome.

Thanks:1zhelp:
 

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Sounds like a very bad case of vapor lock. Where is your fuel line routed. If its close to the motor it will heat up, same as the glass filter. Those have to be the worse filters around, they get real hot very quick, and will break instantly for any reason causing gas to go everywhere (gas fire). You said you replaced the pump, etc. Try routing the line away from the motor and get rid of the glass filter for a plastic one, or get a cool K&N canister one if looks are important. Put a spacer under the carb to keep the fuel cooler too. Just a thought
 

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I have to a agree with dark on this one sounds like a really bad vapor lock. Try the rerouting of fuel lines if possible then maybe try those sleeves that summit and jegs sell that are suppose to keep things cool.Hope this helps,sorry to hear about you troubles.
 

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Discussion Starter #4
Thanks for the tips guys,but I'm kinda stuck as to where I can route the gas line,it's nothin but engine under there.I do have a spacer under the carb though.as for the clear filter not helping any I've had the same problem running a stock autolite carb with screw in filter only it took 45 minutes to an hour for it to cool down enough so I could refire it.what I can't understand is why the problem goes away for a while after I change the fuel pump though?
 

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I'm sorry guys , I'm not sold on the vapor lock. I havent seen a case of vapor lock in about 20 years. The gas additives they use nowadays helps prevent it. At least thats what I've been told.

I would look into maybe a fuel pickup in the tank being plugged or maybe a rubber hose colapsing on the suction side of the fuel line? Or ???? mm
 

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I have been having the exact same problems. I'm going to try one of those fuel line coolers. It looks like a little radiator that you splice into the fuel line.
 

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Discussion Starter #7
Well guys just got back in from playing with the 390 again.I let it run until the gas started to slowly trickle into the filter and checked the rubber lines,they all checked out OK.has anyone noticed that if their car sits for a couple of days the gas empties from the line?I pulled mine off from the steel line by the inner fender and there wasn't any gas in it.after I cranked the engine over a couple of times it filled the filter with gas and I was good to go for about 10 minutes again.this has got me baffled.thanks for the advice to all but I'm still stuck on this one.:confused:
 

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Did you check your fuel pressure and volume?
 
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