Lumpy idle and smell of fuel

[Dave S.]

I had something just like that happen when my alternator died last summer. My 03 Boxster only had 34k miles on it at the time. My mechanic said that the fuel injection system is very sensitive to voltage and he was a little surprised it ran at all. I'd start by checking the voltage across your battery terminals while the car is running to start with. I had less than 12 volts instead of around 13.5 - 14 volts like normal. I think I only showed around 10 - 10.5 volts with the car running when mine did that.
When that happened to my car, the first sign was a strong smell of fuel when idling and a rough idle. I had no dash indicator lights go on, which was really surprising.

[Christian H]

Thank you Dave I'll check that out.