Need some help please

[chance]

I bought the car a month or so ago, thinking it had a blown head gasket. Car was driveable though. I bought another m42 so I swapped out my m42 with a cracked head for the supposedly good one. Car is a 1991 318i.

got the engine in, bolted down, and I think I got all of the electrical hooked up minus the cooling system (was wanting to check for function before dumping gallons of water into it. The car will turn on lights and accessories, but the fuel pump will not prime and the car will not turn over.

Im thinking it might be a ground is missing? But I have the ground hooked up from frame to motor mount, from engine to alternator, and the short one on the starter.
Would having the cam and crank position sensor connectors swapped do this?

Where should I check first?

[bmwman91]

Did you accidentally short anything in the swap process? There is a fusible link that can get blown & leads to this type of thing. The entire fuel injection system runs on a separate 12V circuit from the rest of the car. Is the battery up front or in the trunk of your car? Assuming it is the same between the two...

Get a voltmeter & check the voltage on the terminal blocks up on the passenger side of the firewall. You will see the giant 20mm black wire go to one block, and you should also see a 4mm one that parallels it & goes to a smaller block above this. Check for 12V between that smaller top block & a ground point. If you don't have 12V there, you will need to salvage a fusible link & replace the blown one. This fusible link is in the trunk, in cars with the battery there.

If it is not that, then it is probably just a fuse in the fuse box. I forget which ones are related to the injection system, so either find a service manual or just check them visually.

[chance]

My battery is in the trunk. I do remember seeing those terminal blocks, so I will check them with my multimeter tomorrow.

I also did a quick inspection of the fuse box and so did my friend. We didnt find any blown ones in there.
While the engine was out I was going to replace the blower motor and resistor. While doing it I found that someone had been in there and took out the resistor and tried to hardwire the blower motor... I couldnt come up with any reason to do this... I pulled the blower motor and resistor from a cabrio in a junkyard.

Thanks for the help. It is really appreciated. I hope I can get the car going this week to make it to an autox this sunday.