Looking for Someone with same problem

[Shack55]

90 ka24e starts easy idles fine but when you try to drive it, it starts to buck like a bronc. Still idles fine but give it gas and it like cuts on and off let off gas and it idles fine. I've cleaned every sensor connection replaced all plugs wires new temp sensor all vac hoses this motor does'nt have egr or other emission crap. This all started when i replaced my alt. it also overheated a little came home put water in it now it has this problem. i've read lots of stuff that it sounds like but none of these problems have helped me get mine running right, i've done all the cleaning of connections to no avail. ecm says its fine so i'm really puzzled. Any thing new to look at like ? Wierd stuff to check, please help.

[NismoRb20S13]

fuel pump?