The fuel pump continues to run after the key is turned off. Is this a ground issue maybe? Or an ignition switch problem? I had to disconnect the battery to stop it. So any ideas would be appreciated. Thanks!

 

It would help if you specified which year/make/model/engine.
You can actually put that info in your profile and you won't have to post it ever again.

The fuel pump has a backup power circuit through the FPOP switch (Fuel Pump Oil Pressure). When the engine builds up oil pressure, this switch sends 12V to the fuel pump.
It's common that the switch shorts out, especially if it's still the original switch from 1980's.

Depending on your model year, the switch will be either above the oil filter (newer blocks) or on the top of the block, driver side, just behind the intake (older blocks).

Disconnect that switch and if the fuel pump stops running, that's your problem. They're not too expensive and are easy to replace.

If that does NOT stop the fuel pump, you might have a sticking relay. When you shut off the car, pop the hood, locate the relay (on the firewall, by the brake booster) and tap on it with a screwdriver or something. If it stops, it's probably just sticking. A new relay is less than $10.

Let us know what you find!

Hope this helps.
Lou

 

Its a 91 Transam with a 305. I broke the old oil switch and replaced it maybe 2 months ago, ill try the relay that sounds more likely and easier, if thats not it then ill try the oil unit.

Thanks!

 

Yup, oil pressure unit. Thanks for the help!