What causes an engine to hesitate while driving a 1995 buick rivierra

Check IAC sensor and TPS sensor.

Many of the older vehicles do this and is in essence not a problem. Due to the age of the vehicle the in and/or outlet valves do not seal perfectly causing this puffing. To get rid of it the cylinder head must be removed and the valves need then to be seated again. Costly and unnecessary. Rather check if the tappets are set correctly as this also can cause it. However!! if the tappets are to be found to be set incorrectly it must be rectified immediately as this can cause damage to the valve seats that will result in cylinder head removal -cylinder head overhaul. If every thing checked out fine there is a not so elegant and completely at your own risk option. Take the vehicle out to an open road (Low traffic) Gear up to third gear , increase speed to reach high engine rpm but still driving slow. About 5000 rpm will do. More is OK but please not so high that the engine blows. Maintain this for about half mile and thereafter drive normally for another half mile to cool the engine down. This is done in effort to rid the engine of carbon built-up in the engine and around the valve stems. Sometime it does help and worth a try. High engine rpm is the key but take note excessive high rpm will damage the engine.

do a stall test, like start engine let it run then hold the brake pedal with your other foot raise rpm to put load on engine if you feel the hesitate then it could be spark plugs wire or injectors
hope it helps

you have a bad low idel sencer

check for a bad/loose ground wire in the battery or where it connects to the engine or chassis

you may have a sticky valve in the transmission try adding lucas transmission stop slip

go the cheapest route. replace fuel filter and add SEAFOAM to tank of premiun fuel. replace filter before 500 miles. then add SEAFOAM to gas every 3000 miles to keep lines.engine,fuel pump, and emissions systems clean, ETHANOL problem number 3000

most likely it is not actually a misfire it is the overdrive/TCC solenoid kicking on and off, it is a common GM transmission issue

try change the fuel filter.
and sure there is no abstraction in the air flow from the air filer to the air mixture intake.

accident? inertia switch can cause this prob. loc? gen near floor up near heater assembly on passenger side. might check dealer parts dept. may help locate. ran into this on cadilac.