sshhh

Hi,

Sorry to repost but I dont think I my old post title was getting the right attention.

Ive just completed an LS3 transplant into my e46 BMW and the engine shut off after two sessions.

what is the LED light in the fusebox? Basically my engine cranks but it doenst start, the LED light in the fusebox doensnt turn on. No current in the ECU, so the relays wont turn on. No current in the pump or the ignition.

Cant fault code it because the ECU wont read because there is no power.

It stated for two days but during shakedown gave up on me.

I noticed that I was running super rich as well, Is my aftermarket 280LPH fuel pump to strong for the engine since it doesnt have a fuel return?

I have the GMPP LS3 harness kit on it now. Looking for some help again.

how easy is it to tune this GMPP ECU?

here is my old thread if you want to see photos of the build.

https://ls1tech.com/forums/generatio...ls3-motor.html

rsz288

The LED on the fuse/relay box is the check engine lamp. If this is not on at key on and your fuses and power supply are all ok, maybe a chance the ECM has given up: power on ECM in the right places = LED on.

Have seen this on GMPP harness kits before. E67 ECM was stone dead out of the box.

Do you have a fuel pressure regulator with a tank return?

GMPP ECM's are the same to tune as any regular GM ECM (mostly )

sshhh

The wires in the fuse box were just crimped on, were going to solder everything tom. we found the loose connection.

the engine has no return line.

whats a good software to get to tune the engine?

rsz288

You still need a pressure regulator and return line to the tank. These just dont operate from the engine on Gen IV, they operate at the tank area. Combination Corvette Fuel Pressure Regulator/Filter.

sshhh

Thank you so much!! That makes sense. I'll look into it.