Is there any codes or have they been cleared and is the check engine light on?
I have a list of things that would cause your problem. Please check them out.
Low engine compression
Ignition coil leak or hooked up backwards low,
Fuel pump pressure, should be 9-13 PSI
Vacuum leak, fuel mix will be too lean
Throttle position sensor, out of range or miss adjusted
Spark plugs, incorrect,worn, faulty
Clogged exhaust system, debris inside of pipes or clogged converter
O2 sensors, will result in a lean mixture
Fuel return line, must be not restricted.
Please check these items out and let me know how it goes.