i have a 1991 ef hatch b18b1 swap. ive had 3 different motors in it since owning the shell and now i have an issue with this one . it originally is a dx hatch converted to mpfi and fully converted obd1 harness . i start it up and i can rev it out well past 3.5k for about 10 seconds then it will go into what i believe is limp mode. my ecu is good , i replaced dizzy, plugs,wires,idle air control valve, tps, map, ecu and still find myself having an issue. i did go through my bay harnesss wiring and found nothing that looked to be a bad connection. i currently have my dash out making sure mice/rats didnt get into it and chew up wiring while i had it sitting for several months in my barn . i have the tps wires changed over . i am going to check the volt readings and ground on the tps once i am home from work tonight to see if its even sending a signal to the ecu. any help or suggestions is most definatly appreciated , thanks

 

Did you replace the dizzy with a brand new one? I had this same issue with an EF a few years ago and my dizzy was the culprit. Any check engine light?

 

Id start with going over all your work, id check to see if your map and tps are swapped. Its dumb, but same symptoms. CEL's? Timing? How does it run at idle? Smooth? Rough?