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2007 Silverado Classic possible vapor lock

Old May 27th, 2017, 5:20 PM
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Default 2007 Silverado Classic possible vapor lock

I drove about 150 miles today in 90 degree heat. When I got home, I parked behind my wife. Went to move it about 10 minutes later and truck would not start. Sounded like when not getting fuel. I waited about 30-45 minutes, tried again and it started fine. Took it gas station to make sure it had fuel and it had over 10 gallons in the tank. Truck has had P0449 code for a long time, but never had any issues. I replaced the fuel pump about a year ago due to problems with the tank level float. Truck has 180K miles without a hiccup until today.
Old May 27th, 2017, 6:02 PM
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Vapor lock did occur in older vehicles with a puller (mechanical) fuel pump, and fuel line routing issues especially around "hot" areas of the engine. Your issue is probably fuel related. Fuel rail O ring could be causing it to not hold pressure to start/run, check the pressure regulator, it will have a vacuum line on it. It shouldn't have fuel in it if the diaphram is good, otherwise your having fuel pressure loss through it.
Old May 27th, 2017, 6:03 PM
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next time it happens try to start it in clear flood mode....gas pedal to the floor, wide open throttle. this shuts off the injectors.

one possibility; you may be having fuel pressure leakdown from the injectors causing a flooding condition. the symptom would be crank, no start after a hot soak.

p0449 is not related...you probably need a vent solenoid.
Old May 29th, 2017, 6:37 PM
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Where is the pressure regulator on this truck? I do not see anything on the fuel manifold on either side of the block.
Old May 29th, 2017, 7:50 PM
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its a returnless fuel system...the pressure regulator is part of the fuel pump in the tank.
Old May 29th, 2017, 7:59 PM
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Tech, that is the conclusion that I had come to. Now it won't start at all. I am waiting on a tow truck to haul it my mechanic. THANKS for your help!
Old May 29th, 2017, 8:07 PM
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go hammer on the gas tank with a dead blow hammer and try to start the truck or spray a 3 second shot of brake cleaner into the throttle body...if it starts briefly...you need a fuel pump.


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