My 2001 S80 (2.9) will shut off when I have the car running, pull up to get gas, unscrew the gas the gas cap, the car shuts off. Once filled with fuel, gas cap replaced, S80 will start, but only at 500 rpms, with no response from the accelerator, when the car decides it's ready, it will idle up to 750-800 and the accelerator will respond.

Can anyone tell me why?

Thanks In Advance.

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WBM.

 

Time to check Intake gaskets and PCV Air hoses.

Additionally should check the condition of Ignition coils and Spark plugs.

 

I will do so.

Anything else that I might check?

Thank you for your reply.

 

why are you filling the car with the engine running? Newer cars use a closed system between the fuel tank and the fuel rail. Opening the gas cap with the engine running can drop fuel rail pressure forcing the fuel pressure regulator to compensate - for many cars this can trigger an ODB2 code. Sounds like your ECU could be sensing the issue and temporarily enters a "limp mode". If your car drives normally with no check engine light warnings otherwise, I'd say the car is operating normally and you should turn off the engine while refueling, then make sure the gas cap clicks a few times when reinstalling to ensure you have a proper seal.

 

Fueling with the engine running should not change fuel pressure. It can set a check engine light for an evaporative emissions system leak of the system happens to run the test during that time.

 

ES6T is correct. However, the vapor space of the fuel tank is likely connected to the intake, so a vacuum/intake issue is the most likely to me. I've honestly never removed the gas cap with the engine running before, so its time for me to go do an experiment!

If I were to guess, the idle air control valve (IAC) may be gummed up/sticking/worn out which can cause the engine to die if it overcompensates due to sticking or fails to close and lets too much air in when the gas cap is removed. This assumes the engine vacuum is used to purge vapors from the tank (can anyone verify this?). This IAC issue is pretty common on my specific BMW models and the IAC needs cleaning or replacement every 60k to keep the engine idling correctly.

 

No IAC on that car. I've never seen this problem. A stuck open valve in the evaporative emissions system would have set the check engine light long ago. Make sure there are no codes