Doesn’t start unless I prime with gas/starting fluid

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herb

Not-quite-so-new-guy
Feb 10, 2018
10
9
3
i had the slow start issue on my 78,,,and found the rubber fuel hose from top of gas tank was old-dry-cracked open,,,,,,, but a new hose fixed it
 
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fleming442

Captain Tenneal
Dec 26, 2013
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i had the slow start issue on my 78,,,and found the rubber fuel hose from top of gas tank was old-dry-cracked open,,,,,,, but a new hose fixed it
Agreed. The rubber lines on top of the tank are always suspect. Look for pin holes under the foam insulator, too.
 
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smartin3

Not-quite-so-new-guy
Jul 12, 2020
24
50
13
Michigan
Agreed. The rubber lines on top of the tank are always suspect. Look for pin holes under the foam insulator, too.
Just curious, as my tank and lines are all original. If this were to be an issue for me in the future, would I smell raw fuel near the rear of the vehicle?
 

fleming442

Captain Tenneal
Dec 26, 2013
13,046
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Just curious, as my tank and lines are all original. If this were to be an issue for me in the future, would I smell raw fuel near the rear of the vehicle?
Correct. My clue was the pump not shutting off and me dumping a gallon on the ground at the gas station. If the rubber is cracked, the fuel pump could suck air.
 
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herb

Not-quite-so-new-guy
Feb 10, 2018
10
9
3
i did not smell fumes , since it was a high spot it not drip,, and the pump just
sucked alot of air,,
and as you know the rochesters have the 2 bottom plugs that that leak with age,,,and will empty a float bowl,,,i just used a dab of epoxy over the cleaned and sanded plug
google it ,or buy the book , if you want to want to run carbs forever
 

pontiacgp

blank
Mar 31, 2006
29,270
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Kitchener, Ontario
Correct. My clue was the pump not shutting off and me dumping a gallon on the ground at the gas station. If the rubber is cracked, the fuel pump could suck air.

I have a fix for that, years ago a 4 speed stick Nova winter ride I had developed a leak in the fuel line and the pump was sucking air. My solution for that was to drill a hole in the firewall to pass the fuel line coming from an onboard fuel tank borrowed from my friend. I had the tank on the front seat so I could prime the engine so it would start and once in a while if the engine wasn't sucking enough fuel...it was kinda like a crude fuel injection set up.... :popcorn:
 
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Call Her Bu

Greasemonkey
Dec 2, 2012
109
37
28
Arlington, TX
How hard is it to change the accelerator pump on a 2 barrel carb? Would it just be better to get a new 4 barrel? Should I get an intake for a 4 barrel or would it be fine with an adapter to go from 2 to 4?
 

Bitterman

Greasemonkey
Jan 17, 2017
230
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I could change out an accelerator pump on a 2 barrel carb in about 20 minutes. Now that being said, I've done several so I have experience on my side. Using a shop manual and going step by step, it could be done in 45 minutes to an hour if it's your first time. We can help you through it if you want to do it yourself.

Switching to a 4 barrel would require more time and money and may cause more issues you do not have now. If the accelerator pump is all that is wrong, it's a cheap quick fix for you.
 
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Call Her Bu

Greasemonkey
Dec 2, 2012
109
37
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Arlington, TX
I could change out an accelerator pump on a 2 barrel carb in about 20 minutes. Now that being said, I've done several so I have experience on my side. Using a shop manual and going step by step, it could be done in 45 minutes to an hour if it's your first time. We can help you through it if you want to do it yourself.

Switching to a 4 barrel would require more time and money and may cause more issues you do not have now. If the accelerator pump is all that is wrong, it's a cheap quick fix for you.
Yeah I’ve never rebuilt a carb so help Will definitely be needed lol any advice will be greatly appreciated.
 
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CopperNick

Comic Book Super Hero
Supporting Member
Feb 20, 2018
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An option is to lose the in carb fuel filter and substitute an in line filter. Bigger filter and the do come in clear PVC so keeping track of dirt and crud in the filter is easy to do. Simple to install. Still would not discount the pump as a possible culprit. They can work fine at idle but as soon as demand goes up they fall behind and the motor starves.
 
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