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Q: Went to take the gas cap off and it blew air out.

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Truck won't start without priming the carb. Once it was started we found pressure in the tank. Is this the cause of a bad gas cap or another issue?

My car has 160000 miles.

Excessive pressure inside the fuel cell could be caused by a clogged EVAP canister. This system is designed to filter vapors from the fuel tank for environmental reasons. If the canister is full or the purge solenoid is damaged that releases the pressure, this could cause the starting issues you’re experiencing.

If you’d like to get this fixed, consider YourMechanic, as one of our mobile technicians can come to your home to diagnose your starting issue and help make an accurate repair.

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