Engine Won't Start - No Power to Fuel Pump Fuse
 

I am helping my neighbor troubleshoot his 95 318ti with a standard transmission. He replaced the motor. The car did start and run with the new engine. After a few minutes he turned it off, took it off of the jack stands, restarted it, and drove it just outside of the garage where he left it idling. I am not sure how long he left it idling, but he said after a little bit it started to spit, sputter, and backfire then shut off. It would not restart. He is not an electrical guy so he has been throwing parts at it.

Reading this thread it was like he was having the same exact issue. Unfortunately, there was no solution posted.
http://www.318ti.org/forum/showthread.php?t=34631

There is no power to fuse 18. All grounds are good. The DME, fuel pump, and oxygen sensor relays have all been replaced.
The DME relay energizes correctly, but the fuel pump relay and subsequently the oxygen sensor relay do not (pin 30 of the oxygen sensor relay is fed from pin 87 of the fuel pump relay). I have traced the wires going from the relays to the DME and they all have good continuity so there is no break in a wire.

The cam and crank position sensors are new, fuel pump is new, temp sensor is new. I can jump the fuel pump relay and you can hear it working.

Pin 85 on the fuel pump relay that goes to pin 1 on the DME always has power to it. Unlike pin 85 on the DME relay. That shows power, but when they key is turned to ACC the voltage drops to .8 VDC and the relay is energized. I suspect that the DME is not removing the power to pin 85 of the fuel pump relay like it should to energize the relay. But why isn't it doing that? What other input to the DME is causing it not to remove the power to energize the relay?

I may have forgotten some things we tested and readings I took, but if anyone has any questions or suggestions we are all ears. What boggles me is that the car ran and ran strong for what little time it was running.

A little update.

I have had a bit of I am an idiot moment. I do get power through the fuel pump relay and to the fuel pump fuse. When I was previously testing it I was doing with the ignition in ACC. When I try to start the car the relay energizes and provides power to the fuse. However, the car just cranks and cranks. If I just keep cranking it every once in a blue moon it will give me a little sign that it wants to kick over. When it does that the RPM gauge jumps up to about 3-4K and the mpg gauge jumps as well. Other than when the engine gives that tiny sign that it wants to kick over the gauges do not move.

I also tried to see if there were any codes stored in the DMC. I never get the initial sequence of initial sequence of flashes. The light will stay illuminated for 2.5 seconds, give a quick flash, stay illuminated for 2.5 seconds, give a quick flash. It will just continue to repeat that pattern until I turn the ignition off. The owner of the car even tried a scanner and he said he couldn't pull any codes.

After testing just about everything in the car a friend of he owner was able to get a hold of a DME.

WE HAVE A RUNNING CAR!!!!
As soon as we plugged it in, cranked the car, it came to life and ran smooth as butter.

He said the DME we had was for a 6 cylinder. I question that. The VIN that is on the computer matches the cars VIN. Decoding the VIN it shows to be a 4 cylinder car so I don't understand how it could have changed. Regardless, the car runs so it really doesn't matter to me.

Pic of the DME that works.
https://i.imgur.com/9gM4V9y.jpg