Hi. Recently rebuild motor by dropping subframe. Now I have no ecm + or power to the the fuel pump relay. When I jump the ecm to the batt. Engine has inj pulse and spark as it should. If I prime the fuel pump the car will run for a short duration then quit even with constant power to the prime. But the issue is why am I not getting power to the ecm or fuel pump relay block. power is at the fuse box No popped fuses. Where do the ecm hots connect to the fuse box or where does it disconnect when dropping the subframe.

also if I just rewire with relay to ecm power switched on ignition. and do the same to fuel pump will it run right or eill there be fueling issue

 

Need to know the year of the car.and year of computer if not the same.

Here's a set of 95 PCM schematics. PCM grounds are on sheet 1, 12V power to PCM, and fuel pump relay are on sheet 3. But other years may have a different location for the “PCM BAT” fuse. If you are using the ECM (rather than PCM) designation because it's a 93, it's quite a bit different.

4th Gen LT1 F-body Tech Articles

EDIT: I see you already posted this problem earlier. I responded there. Please keep it all in the same thread, You had the PCM info in that post. Add a “signature” so the info is always attached to every post.

https://www.camaroz28.com/forums/lt1-based-engine-tech-9/no-fuel-no-spark-after-rebuild-889294/

https://www.camaroz28.com/forums/lt1-based-engine-tech-9/you-need-signature-879835/

 

Yeah I split it Bc it’s specific issue now, my bad. It’s a 97 with 95 ecm. Verified all grounds and have those two hots jumped straight to 12 v and it ran.

Do you know where the ecm splices with the fuse box for power. Or I guess where it was unhooked when I dropped subframe?

 

Check
C210 cavity C Orange wire Power feed from PCM BAT fuse to PCM

C220 cavity E Pink wire Power feed from PCM ignition Fuse #13

These are in the RH kick panel

http://shbox.com/1/harness_connector_faces.htm

 

Further to the above, from the 1996 factory service manual (97 is virtually identical) the C220 pink wire has a splice (S132) in the engine compartment. That splice is located in the engine harness, PCM breakout bundle, about 19cm from where the PCM bundle branches off from the rest of the harness.

Free factory manual download:

http://www.mediafire.com/?40mfgeoe4ctti