my 1990 RS will used to start and stay running for a while, but then when i would drive it about 5 minutes into my trip it would just die and not restart, or if it did it was only for a few seconds. now when i go to start it it will fire up and then just die. sometimes it sputters a bit and ill try to give it gas and it will just die. i have good fuel up to my fuel rail. im pretty sure its electrical. maybe something with the distributor or the coil pack?? please help.