87 Cabriolet starts and dies ?

Hi I just replaced the feul pump on my 87 cabrio because it died on me the other day. After reinstall car will now start but only runs for 20 seconds and dies ? checked the feul filter and it's pretty old but I couldn't get another one for a couple days, so I blew it out and put it back on. Same results, starts but runs for short period and shuts down ? any help !