S52 swap OBD1 troubleshoot

[nikeobeys]

I have a 88 vert that previously had a m52 in It.

Just swapped a 98 s52 motor with m50 intake manifold and obd1 harness, I swapped all for obd1 configuration. Car cranks but no fuel or spark...

-fuel pump works I tested It
-replaced main relay & fuel pump relay
-I have voltage going to the relays
-cps is reading .550
-ICV has constant voltage when key is off and has a humming sound.
-Tried swapping to another red label 413 but same symptoms

[ForcedFirebird]

Check voltage coming out of relays with key on/off. White stripes on red is switched power.

Since no spark and no fuel, suspect CPS signal, bad/wrong relay, no DME power.

Easy/fast way to test DME is getting power is key on and the ICV will buzz/vibrate.

Check CPS signal at DME connector, not at the sensor wire end.

[e30austin]

ICV humming without switched power being activated, makes me think you have something wired incorrectly at the battery distribution block.

[ForcedFirebird]

ICV humming without switched power being activated, makes me think you have something wired incorrectly at the battery distribution block.

Good catch. I missed that in the read. Sounds like there may be a ground/power reversed.

[nikeobeys]

The ground connections I’ve checked so far
-engine mount to chassis
-ground from engine harness to battery
-ground from fuel injectors
-starter