Fuel pump or carb

[LilSpann601]

Whats up I im having problems with my monte carlo again. Heres the story the car runs fine for about 30 mins then all of a sudden car feels like it runs out of gas.So when i pop the hood and move the accelerator fuel barely shoots out the nozzles or sometimes it wont. if I disconnect the fuel hose and turn the engine fuel starts to shoot out the line after a turn or 2. If i let the car sit for a while and start it the car runs good for another 20 mins or so..Im thinking its the carb I had it rebuilt about 2 years ago but I never put any miles on it....what do u guys think

 

[565bbchevy]

I would say if it runs good for 30 minutes and there are no fuel leaks then the carb is most likely fine, it could be fuel pump related or a vapor lock or heat soak issue and it could also be a venting issue with the gas tank.

 

[Texas82GP]

See if it will run ok without a gas cap for more than 30 minutes to see if it is a fuel tank venting problem.

 

[LilSpann601]

Ill try running it without the cap. One thing I do know the line running from the tank which is the vent I plugged it with a bolt a long time ago.

 

[Texas82GP]

Ill try running it without the cap. One thing I do know the line running from the tank which is the vent I plugged it with a bolt a long time ago.

Then tank venting is likely the problem. If it runs ok without a cap then you have a few options. One, you could get a venting gas cap. Another option is you could unplug the vent line and put a small differential filter on the line to keep trash out and it also keeps the car from smelling like gas. There are guys on here that have cut the line back to a good place under the car and then put that filter on.

 

[Texas82GP]

I think this is an example of the vent filter some have used. I've also heard of small fuel filters being used.

https://m.summitracing.com/parts/aaf-all36103

 

[-83MONTESS-]

I cut that line right above the rear end and put a cheap autozone valve cover breather type filter on it. Worked good for me. The only issue I had when I had it plugged was it seemed the car was harder to start.

 

[LilSpann601]

I ran the car without the gas cap for a while. The car did the samething acts like it ran out of gas..If i let the car sit for about 30 mins to an hour it will crank back up and run...when car does stop running barely any fuel squirts out the accelerator pump

 

[monte olrac]

most likely your carb is getting hot and boiling the fuel right out the bowls, you probably have a fuel pump going bad too, try a plastic or phenolic carb spacer

 

[monte olrac]

Tell us about your setup, and what temps does the car run