Mister Will

I was just responding to the thread about poor gas mileage with an LS1. The subject of running low on gas came up. I have always heard that if you run out of gas in a FI vehicle, a shop is needed to start it again.

I was wondering if this is true or an urban legend. I'm no mechanic, but some how gas has to be fed back to the injectors. I have heard that if you run out of gas. A vacuum is created in the gas tank and a check valve shuts off the supply. It's a safety feature to prevent gas from being dumped out during an accident should the line be broken. So it has to be reset in order to start the engine again.

I remember with my LT1, I was so low on gas that it wouldn't stay running. It would start right up, run for 15 seconds then shut down. It did this again and again. Perhaps the CPU shuts the engine down before the tank goes dry?

What needs to be done to restart an LS1 F-body after the injectors run dry?

Edit: Well I would still like the above question answered. But I just remembered. If you run out of gas in an LS1, your fuel pump is fried. It will then need to be replaced. I should know this because I had this happen to me during a test drive. Ran out of gas a block away from the dealer. Had to come back a week later to complete the test drive.

PhantomTA

the only shop that is needed is the one thats going to replace your now burnt up fuel pump

hurricaine418

ive only ran out of gas twice, once by accident the other intentionally. the first time wasnt a ls1 but a '94 v6 3400 series. the gauge stuck at 1/4 tank and did what you mentioned by shutting off every 15 seconds. (sees too low fuel pressure) i had my ls1's fuel pump upgraded to handle turbo chargers. the tank was ran down to help with the installation. ran down too far and needed a gallon to get the car over to the speed shop. i didnt kill the existing fuel pump tho, started right up with the gas. maybe the car you test drove had other issues.

Rogue Leader

thats an intertia switch that shuts the fuel pump if in an accident. I triggered it when I spun out and locked em at an autox once. Wait about a minute and it will start again if you trip it.

hurricaine418

yeah, they really suck on fords, hit a pot hole and the car shuts down.