weird fuel pump problem
 

hey guys
i've been working on my car for about a few weeks now and now i'm stuck and could use a bit of help or point in the right direction.

long story short after my mt na 2+2 z31 had the battery put in backwards (reverse polarity) the ecu and black linkable fuse burnt out. so i replaced the fuse and found a ecu out of a 86 at na z31 at a pick n pull. after installing everything it started up but died after a few seconds. so i decided to do a fuel pressure test and when the pump primes it comes up to 42 psi but once i used up that fuel no more is pumped into the cylinders. i checked the fuel pump relay and it clicked and everything. i even pulled codes off of the ecu and it gave me 13 and 41. i know the fuel temp sensor code is because my dad broke the connector. i don't think the chts would stop the engine from running.

well i'm pretty lost at the moment so any help would be greatly appreciated.

is your car an 86? there are differences between years. You may have burnt out some other components with the reversed battery. did you open the cover to the replacement to be sure it doesn't have some burnt components. fuel temp sensor won't affect your car in any way you can detect. get the schematic from the fsm free at xenon and get it enlarged to 11x17 at Kinko's. start tracing wires and testing.

Oh sorry about that mine is an 85. I think the only difference is that the o2 sensor is different