Gas Tank Keeps Building Pressure.

Subject: Gas Tank Keeps Building Pressure. Fri Apr 30, 2010 8:16 pm

Has anyone ever had a problem with their b-body not starting because of excess pressure in the fuel tank. Every once in a while the cappy won't start. I get out and open the gas cap and woosh, a rush of air comes out. Then it starts right up. The other day it wouldn't start so I tried it to no avail. I realized I did not hear the fuel pump. I whacked the gas tank and it started right up. Could this be the result of a malfunctioning fuel pump?

Subject: Re: Gas Tank Keeps Building Pressure. Fri Apr 30, 2010 8:24 pm

Mine only makes that whoosh if I've run the tank really low. Is that the case with you?

Could be the gas cap, possibly.

Have you checked the fuel pressure at the rail when it happens?

Do you hear the fuel pump turn on when you click the key to "run"? It should come on for a few seconds and then shuts off.

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The whoosh is normal & changes with the purge solenoid
http://shbox.com/1/evap_sol.jpg
You can read up on how it really works but I refuse to learn that til I have to.
Whacking the fuel tank does free up a hung up fuel pump
Do you run the car low on fuel alot?
Once a fuel pump starts hanging up get rid of it, the filter & harness

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Steve
Gas Tank Keeps Building Pressure. Impala2010002

96BBB 28K 3.42 Bolt-ons
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Subject: fuel pumps going bad after 100k miles Fri Apr 30, 2010 8:39 pm

my fuel pump started malfunctioning at about 105,000 miles if thats any help

Guest

Your evap system is not working correctly.

Subject: Re: Gas Tank Keeps Building Pressure. Sat May 01, 2010 9:33 pm

my caprice is having a similar problem. sometimes i get no fuel pump prime when i turn the key = no start. I go under my hood and manually prime it to get it started. Doesn't happen every time.

Subject: Re: Gas Tank Keeps Building Pressure. Sat May 01, 2010 9:41 pm

GasTT wrote:: my caprice is having a similar problem. sometimes i get no fuel pump prime when i turn the key = no start. I go under my hood and manually prime it to get it started. Doesn't happen every time.

try a new relay

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