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MagmaJct · 08-07-2011, 08:04 PM

I think Gary may be referring to a gas cap that's vented one way, that is, it allows air into the tank to replace the gas that's being pumped out. If there's no venting it would be like trying to drink from a glass soda bottle without letting air in, you'll stop getting soda!

However, I am not sure of the specific details on how the evaporative system is vented in these trucks, so I will share my experience.

I had symptoms of vapor lock as you are experiencing now. I live in the desert, and it would "lock up" during the hot days here. But eventually it would do this at night when it's much cooler, (in the 90s!)

Then, it wouldn't start at all, I diagnosed the problem as a bad fuel pump. When I replaced the pump about a year ago, I haven't had a SINGLE no-start condition since, regardless of the temperature. I think another poster on this board had the same symptoms, and it ended up being the pump.

I can't say that it is your pump, but that would be the direction I'd look.

08-07-2011, 08:04 PM	#4
MagmaJct Registered User Join Date: May 2008 Location: Mesa, AZ Posts: 281	Re: Fuel Delivery Troubleshooting I think Gary may be referring to a gas cap that's vented one way, that is, it allows air into the tank to replace the gas that's being pumped out. If there's no venting it would be like trying to drink from a glass soda bottle without letting air in, you'll stop getting soda! However, I am not sure of the specific details on how the evaporative system is vented in these trucks, so I will share my experience. I had symptoms of vapor lock as you are experiencing now. I live in the desert, and it would "lock up" during the hot days here. But eventually it would do this at night when it's much cooler, (in the 90s!) Then, it wouldn't start at all, I diagnosed the problem as a bad fuel pump. When I replaced the pump about a year ago, I haven't had a SINGLE no-start condition since, regardless of the temperature. I think another poster on this board had the same symptoms, and it ended up being the pump. I can't say that it is your pump, but that would be the direction I'd look.