Engine turns over, then stalls. Checked all fusible links, no issue.  Fails first test of the EFI bible...no power at the plug to ECU..  Could use some advice, please.

Do you mean that the engine spins via the starter then stops spinning?  Or that it actually starts then dies?

There 35 pins at the ECU plug.  Which don't have power?  And did this happen out of nowhere?  It was running fine?

The EFI system has its own fusible link, attached to the battery positive post.

Zed's suggestion on the EFI fusible link & also the EFI relay would be were I would check.

Yes, Zed, car has run fine for a few months.  Installed a sound system and shorted something out.  Car turns over, runs, then stalls.  Fuel pressure around 30 psi, before stalling.  Fuel pump cuts out  No tach, no alarm buzzer when key is turned to on.  With key on, pushed AFM flap, fuel pump does not engage.  Fusible link is fine.

 

Where did you tap in for power to the new sound systems, did that system include a high powered amplifier?

(now it's in the right place)

Amplifier positive to battery positive, negative to body ground.  Receiver (radio) to the six pin connector.  Both work fine.

 

55 minutes ago, rosaluma said:

Fusible link is fine.

How do you know?  They're designed to stay fine on the outside while the inside self-destructs.  Silicone insulation.

Did you reconnect the correct connectors at the battery post?  The plastic snap-in ones?  One is ground and one is power (with the fusible link in-line).

Sounds like you either know something shorted, you saw sparks, or you're assuming.  The thing below implies EFI fusible link.  I think that the combined EFI and pump relay are on that link.  Good luck.  You really need to measure things to know, it looks like you're just eyeballing them.

" With key on, pushed AFM flap, fuel pump does not engage.   "

9 hours ago, rosaluma said:

Engine turns over, then stalls. Checked all fusible links, no issue.  Fails first test of the EFI bible...no power at the plug to ECU..  Could use some advice, please.

If I read your first sentence. My first place to look would be the AFM switch. You have an early 77 with the fuel pump activation in the AFM where as from Aug 77 it used the oil switch.

Then you mention you don't have power to the ECU. Zed Head is right about the fusable link looking good, but really blown under the silicone insulation. It can be very misleading.

Easy way to check is with a test light. The fusable link has a spade terminal between it and the red wire going to the ecu. Disconnect it and see if the test light works. 18Watt bulb would work good to load the fusable link. You could also check voltage drop over the fusable link while testing with the bulb.