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.