the surge the engine does when you first start it up is normal, the engine is built to do that to assist with warming up the system it should lower after 30secs or so.
There are just too many of the one or two of the devices on the car that would be causing this. Go to a tune-up shop.
the engine to stall and surge at idle
auto or stick shift
Probaby a sensor.
To adjust the idle on Mazda 929 from 1992-1995.......on the top side off throttle body there is a idle air screw,turn screw cloclwise to reduce RPM. Question...is idle always high when hot or cold?
The Idle Speed misadjustment, Timeing misadjustment, or bad throttle position sensor. Search one of the 4WD forums like IH8MUD.com or Pirate4x4 for idle surge. check the coolant level.
I had the same problem and it turned out to be the fuel purge censor
maybe the clutch
The idle speed on a 1987 Chevy Celebrity is controlled by the engine computer, there is no way provided to adjust it.
A power surge under a load is probably the transmission slipping. If its a manual transmission the pressure plate is slipping on the disc. If it is an automatic most likely it is a worn clutch pack slipping. If it surges at idle with the tranny in park the surge is usually a defective IAC (Idle Air Control) valve.
A large vacuum leak can do that.
go on line search Mazda parts