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1990 miata with 6port 13b with holley 4 barrel carb

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Old Sep 20, 2014 | 06:50 PM
  #1  
tytemf5's Avatar
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grease monkey
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From: atlanta, ga
GA 1990 miata with 6port 13b with holley 4 barrel carb

hi guys, i am thinking about getting this car as its pretty unique and i miss having a miata. the only problem with the car though is that after filling it up with gas, the car has a hard time starting and staying on??? after i guess cooling off, the car will stay on and start with no problems until it is time to fill up again... the fuel pressure on the holley 4 barrel carb is 6psi. is this a common problem with carbs? any tips?

thanks,

marlon from atl
Attached Thumbnails 1990 miata with 6port 13b with holley 4 barrel carb-13bmiata.jpg  
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Old Sep 21, 2014 | 08:14 AM
  #2  
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it only behaves that way after you fill the tank? does it start and run fine all other times?
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Old Sep 21, 2014 | 10:26 AM
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..
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Old Sep 21, 2014 | 06:52 PM
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Its got to be the paint job!!!! lol
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Old Sep 21, 2014 | 07:54 PM
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Probably a problem with fuel tank venting and fuel pressure.

The carb'ed rotaries are super sensitive to fuel pressure.

It probably needs the pressure that builds up in the warm gas tank to run right. Make sure the old fuel injection return line is open vented and then retune the fuel pressure up a bit to make up for the pressure lost to the carb from a non-pressurized gas tank.
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Old Sep 21, 2014 | 09:56 PM
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How can you assume it is vapor lock
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Old Sep 21, 2014 | 11:40 PM
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From: Pump Handle, SK. Canada
6 psi should be more than enough . Is there a carbon canister on the car ?
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Old Sep 22, 2014 | 11:14 PM
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grease monkey
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From: atlanta, ga
it only behaves after filling up yes. i dont know if there is a canister. this thing guzzles gas though!
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Old Sep 22, 2014 | 11:23 PM
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just a shot in the dark but maybe could check if it does have a canister and if so make sure the hoses are routed properly .. just a thought but it won't cost anything to check it out .

i guess they aren't the easiest thing on fuel but it shouldn't be so bad that it keeps you awake at night .
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Old Oct 3, 2014 | 06:27 PM
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If you decide to pass on the car, let me know
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