It is hard to start.but when it does, i can not press gas pedal rapitly. it can run only 50 mph. at stop light, quick tap on gas pedal it die right away. i have changed all new. spark plug , wire, distributor cap roto need help

I'd check the brakes and the wheel bearings. Just everything in the suspension on that corner. It could be a number of things, but I definitely wouldn't drive it until you check it out.

Your car cold start valve puts more gas into the system keeping your engine running higher RPM. When you car warms up, the cold start valve will stop working and your car RPM will drop. What you could have is a vacuum hose disconnected which puts more air into your engine - therefore when you press on the gas pedal, your engine would shut off or you find lack of power and then shut off.

Has the engine light come on yet?

Transmission band slipping.

You mean PCM most states read the readiness monitors depending on the state on how many they allow not to be completed. The first one on the list that is hard to get run and pass is the EVAP Because this requires the car to be cold and fuel tank must between 15%-85% and both air temp and coolant temp with in 10 degrees of each other. Start car let idle for 5 -10 minutes Then drive car normally no hard accelerations or quick stops bring speed to 50-60 mph and coast down to 20-15 mph without brake pedal input repeat this twice.Then bring speed to 58-62 mph and set cruise control run for 12-16 miles exit freeway caught a red light or stop and idle 2 minutes shut car off rest for 5 minutes and repeat freeway drive. then redo morning cold start again . then have some one test the generic readiness monitors to what needs to run and attempt again. California before 2000 1 can be incomplete after 2000 all have to be completed which is hard some will not run for 800 miles.

Check for vacuum hose leaks

does thr engine rev upwhen started than idels back down.try idel control switch and map sensor

try to take it to a garage for scan so as to know the problem.but to me it seems thorttle mouth fault.

I had a similar problem. The dealer change automatic transmission and differential, but the noise continu. After research on internet i think the problem is the front galiper who create a vibration on the disc wheel and the vibration frequence follow the front axle until interior car. Just press slowly the brake pedal and if the noise stop , that's it the cause i think. I dont change my galiper, but i have a new transmission . :)))

I would take a look at possiable damage to the PCM (powertrain control module)