Thread: Help!!!! No fuel No spark

Hey everyone. So this isnt a typical no spark no fuel issue. Let me start from the begining. So i picked up an sr swapped 91 nissan sentra xe. i started driving it home and blew the motor due to 3 1/2 missing quarts of oil. So i figured it was a good time too swap a det into it.
Fast forward to the next day. i just finished dropping in the det. before i got the ic piping installed i did a test start and she fired right up. this is with stock maf and ecu from the na sr. anyway i get her put together and she feels amazing on the road. As i get home from the first test drive she starts bucking and dies. i take a look under the hood and my maf came unplugged. plugged it back in and she fired right up.
so next day i decide to drive it to the gas station and fill her up with gas(91 octane) as im driving back and on my way back she dies completely. i push her home (half a mile of up and down hills lol). So i start checkin the basics fuel and spark. Nothing no prime no spark. so i checked fuses under the hood and in the cabin and they all check out good. Next i check relays and grounds. still check out good. So after everything i decide to start from scratch. replaced everything to us sensers and replaced coil, distributor, coil, transistor, and fuel pump and ecu. I even switched injectors and went back to na to aid in iscolating the problem. Still nothing.
So i decided its time to break out the FSM. After numerous hours of testing i find out that im not getting a starter signal to the ecu. but instead it was grounding out so i ran a new wire to the ecu to a 12v switch source And still nothing. Ive owned and swapped motors on 5 seR'S and never had any issues like this. All connectors are connected. Still nothing. Im lost now any one with any advice? Im ready to torch this B. PLease help
also every thing gets power when i turn on the switch just nothin switches on????

well if the ECU isn't turning anything on, my gut tells me the ECU grounds on the IM aren't in good shape. Maybe grounding them directly to the battery ground via a test lead could help figure it out. Since you say you replaced the +12v for the ECU, I'd look into the ground connections.

Awesome thanks im going to go check out right now thanks.

pin out 34 on the ecu was grounding out and power was non existent. like i said before so i hard wired it to the battery and she started right up! so anyone who has this issue make sure your ecu has power! this was after 3 sleepless nights literally lol now for some well deserved sleep

oh and pin 34 is your ecu start signal and supply

You'll want to move that connection back to the intake manifold and make sure the engine is grounded properly. The ECU should not be grounded directly to the battery. The intake manifold and engine (large chunk of metal) buffers a lot of voltage noise out.

This. Wiring direct to the battery just helps you find where the issue is, not as a means to solve it.