92 Mustang, just install TC 2.3, need help

OK....I just swapped a 88 TC 2.3 into my 92 Mustang using the instructions posted (linked) on this site. It started right up on the first turn of the key , but.......it won't rev over 3000RPM . I had the EXACT same problem with the 2.3 NA engine I pulled. Am I correct in guessing it's proabably a bad feul pump? I changed the fuel filter which was VERY dirty, when I removed it brown gas dumped out. I have put fuel injector cleaner in the tank. Is it worth it for me to drop the tank and change the pump? or should I look elsewhere for the source of the problem?