300 se dies then is hard to start

[SCOTTFISH]

I have an 89 300se. Sometimes when you put it in reverse and start backing up, it will choke and stumble some and when you stop and put it in drive, it sometimes quits. Then, it is hard to start for a fews seconds. I can eventually get it started by pumping the gas. Could this be a bad fuel filter or fuel pump? It does not do it all the time, but when it stumbles and quits in reverse, you can almost bet 99% of the time, it will be hard to start until you get it started. Then it is fine. It will run fine and will not stumble anymore. It seems like it does it when the car has been sitting for a few minutes or overnite. Any suggestions?