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Gmc Sonoma | Can A Loose Gas Cap Cause Low Fuel Pressure And Stalling Out?
Category: Maintenance & Repairs. Num Answers: 4
2001 gmc sonoma stalled out while doing 70mph on the highway, about 30mins after refueling. Had a hard time starting but it eventually did, then drove half a mile, then stalled out again. Oil guage, temp guage, and the volt guage all read normal. Didnt see any problems. A friend tightened the gas cap and we never had another problem again driving from kentucky to florida. I have a hard time accepting the gas cap was the problem, What do you think? Thank you!
Answer by Carroll
Not likely that a loose gas cap would cause that. Low fuel pressure would be caused by a clogged fuel filter, faulty fuel pump or leaking fuel line.
A loose gas cap would cause your engine light to come on and an EVAP code to be set in your car's computer.
Answer by Country Boy
Gas caps or lack there of has nothing to do with fuel pressure at the fuel rails. You'd better change your fuel filter and if your problem persists, have the fuel pressure read at a Chevrolet dealer. You may need a new and improved fuel pump in the gas tank.
Answer by Michael S
Because you didn't say that you tested the fuel pressure in any way, I have to assume you really didn't test fuel pressure and you're just guessing you have low fuel pressure.
Yes a loose gas cap can cause the engine to act the way you describe, as it was trying to correct it.
Answer by Bsnodgrass2003
Yes it's the cap. It is a vacuum sealed system. In some vehicles it will cause the check engine light to turn on....this can occur when pumping gas with the car running or ignition on wil cap off....it is still sending data to the cars computer.