Oldsmobile/Buick Repair: idle high, vacuum leaks, oldsmobile 88

Question
i have a 1993 oldsmobile 88 6 Cylinders 231 L 3.8L SFI that is idled very high when in park i tap on the gas it idles down, but then is very high again. less than a half tank of gas it wont stay running. thanks in advance

Answer
Hello Young,
The combination of symptoms sounds like a fuel pump problem, possibly a leak inside the tank or a weak pump.
I wouldn't just replace it...I would connect a fuel pressure tester, and see what the pressure is, especially when the fuel level is low.

If the fuel pressure is low, there could be a lean condition, and the computer could be trying to compensate for that. Just a guess. Check the pressure.

Vacuum leak is another possibility. Clean the EGR valve, and check for vacuum leaks.

Van