When cold my 93 chevy rbenjamin harrisonuns rough

Most likely your getting poor fuel economy too. The temperature sending unit/sensor is malfunctioning and the computer doesn't know any better so it's keeping it in cold start mode. Like the choke is still on at all times.

Could be bad EGR valve or vacuum leak. Egr valve, depending on whether it is stuck open or closed can act like the old choke thermostats on the carburator system making the vehicle run and idle rough when it is cold OR hot but normally only one or the other. Will run fine cold but rough once it's hot or rough when cold and fine when hot. Check or have someone check for any trouble codes in the system. It can hold codes and not make the check engine light come on and may help diagnose the problem.

Need year/make/model/mileage of vehicle to provide a more specific set of troubleshooting steps.

When was the last tune up? Hard starts when cold are usually caused by fouled spark plugs, worn plug wires, or weak ignition coils. Fuel systems are not as effected by temperature changes as the ignition components.

Check the choke when cold. When its hot take notice that its opened. Upon starting next time when its cold look at the choke and see if its closed fully. It should be. If not push the throttle all the way open and let it retract closed. The choke should close when the engine is cold. If it does not the vacuum break is shot which should be the rear one that controls the choke. Yours may be on the front since some are but very few are made on the front

Check the coolant temp sensor (the one that speaks to the ECU) which acts like the choke on a old carb type engine. These can be tested with a multimeter by dunking them in different temp water.

Bad Ignition Module

Hello;
The injector assembly also contains the pressure regulator. Since the truck has been sitting, you may have some corrosion in the regulator and the injectors. Try a fuel cleaner and the work on the regulator.
Thanks;
Rich;
RPM Northwest

If its equipped with fast idle valve, try to replace it. You may want also to check your TP valve.

is it an auto choke if so it may not be working some cars have a cold start which is on the inlet manifold and some are in the carbs them self but i think it is not working so that is why it runs rough when cold hope ive helped you