M52 b28 swap with obd1 413, no start

[papajetta]

I have a 1991 325ic formely automatic , 5 speed swapped for the past 2 years. Saw the engine running before I baught it, from an automatic 98 328i. Saw the car with the dme and harness also running, from an automatic 1994 525i.
Completed my swap, go to turn it on and no start . Find there's no ground going to the fuel pump relay from my dme. If I jump that ground fuel pump turns on and car starts. Apart from the 2 grounds coming out the passenger side of the harness, are there any other grounds I might be missing?

[volktek1]

car

mine did the same, heres was the problem. Check the resistance from the ground wire at the fuel pump relay to pin #1 at the ecm, i bet you it it an open circut. overylay the wire and i bet you car will start,

[papajetta]

Thanks for the response. I will as soon as o get back to the garage. I was just looking over the bentley manual. The transmission range switch input into the ECM has always been in the back if my mind, as I havnt been able to find a clear explanation for it. On the manual transmission, ECM pin 81 gets a fused b+ on run and start. The same exact signal goes through the range switch first on an automatic, switching on when in P or N. The same exact wire ( brown / black ) tees off towards the cruise control module and the starter immobilization relay. Does anyone know exactly what function does this serve going into the ECM? Could it be a backup for the starter kill, cutting off the fuel relay also?

[papajetta]

That did it guys..... Sent power to pin 81 . Voilà . Pump comes right on.