97 Grand Cherokee Laredo V8 wont stay running
 

I am in Plano Texas and just got burned when I bought my 97 GCL Jeep. When I got it home it does not stay running took it to my mechanic and he told me they lied about rebuilding the engine the plugs were horrible and oil was like tar. Air filter was black so put $370 in it and still no go it starts with no issue but as soon as I take my foot off the gas it dies. Any suggestions:bangin:

Sounds like a bad tps (throttle positioning sensor).