Q: 91 mazda b2600i When you press gas when @ idle it wants to cut off, when you let off gas it picks back up & no power when driving.

What you are describing is loss of power as well as near stalling. The cause of that fault can be diagnosed, and any required repairs made, if you request an engine loss of power diagnostic. To give you an initial idea, although there are many possibilities, a partial list of causes would include faults with oxygen sensors, fuel pump and/or filter, vacuum leaks, ignition system malfunctions, bad valve timing if the timing belt or chain is worn or skipped, blocked exhaust (e.g., catalytic converter fails or becomes clogged), airflow sensor, throttle position sensor, and so forth. Whatever the cause, if you request the engine loss of power diagnostic, the certified mechanic will get this resolved. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.