Stalls at low speeds :(
1991 Grand Prix GTP 3.4L V6 DOHC stalls at low speeds. It doesn't happen all the time, maybe once or twice a week. It sputters, RPM guage jumps then it dies and won't start for about 15-20 mins. Changed plugs and wires, cleaned IAC and throttle body but didn't work. Fuel pump, fuel filter and oil pump are all ok. Banging my head against the wall here. No mechanic can figure it out. Been hooked up to computer but no codes.