1988 pu 4.3 replace plugs wires cap roter runs worse

Sounds like timming to me?

Does it start right back up ?
Are you loosing spark to the plugs or fuel to the injectors ?

The firing order is 1-3-4-2

is your firing order correct? it should be 1-3-4-2

check and replace fuel pressure regulator

If you are sure they said, a distributer cap a roter and a distributer, there is a problem! Because on a 1998
plymouth, there is no distributer or cap or roter.
Your cam sensor along with the crank sensor-temp sensor and a few other sensors, send a signal to the
powertrain control module, that sends a signal to the
coil pack(that you said was replaced) that fires the
spark plug. I would hold off from having any further
work done there, until you can check out what they
say they have already done. Ask if you can have the
old parts they replaced so far. You will want to have
an OBDII scan test done, to see what codes come up. It should have one of the first tests they did.
If I have read your post correctly, have them write an
estimate for what they will replace next. This info. is
based on the car being a 1998 plymouth and not a
1988 I would not wan't to acuse somone of anything
based on a typo. Hope this helps. Good luck.

change the pickup coil in the dist. or change the whole dist

when you replaced the plugs/wires. Did you do the cap and rotor too
Also have your timing checked

did u change the fuel filter? this is a common symptom of a filter that is almost plugged.

computer wiring could be bad /computer bad..should be spitting codes....tired motor / internal damage ? timing chain/gear set up improper?