NEW engine. Certified and inspected, broken in.
NEW starter.
NEW fuel pump.
NEW battery.
NEW coil packs.
Put in my new engine over the weekend and when finished started right up like nothing had changed. Drove perfect for about a day. Parked it at home, suddenly wouldn’t start but would crank for days. Had gas, fuel pump seemed to be struggling. Replaced. Got code C1109. Replaced battery and every fuse and relay related to ignition or ABS.
replaced the coil packs, nothing. Weird part is ONCE in a while it will fire up and run for a while but then die again with the same problem. It will just crank. Help.

 

Something isn't hooked up properly, something electrical. Verify the chassis to engine ground (below coolant reservoir to timing chain cover) is on and has CLEAN connections.

Are you sure it's not NATS/IVIS, you would have a solid red security LED indicator while cranking if it's a NATS problem.

Did you reuse all the existing sensors or did you buy new ones? Double check there's no hidden/pending OBD2 codes for cam/crank sensors they WILL prevent the engine from starting.

Does it crank weak or does it just not START while it's cranking?

Z1 Motorsports makes a VQ fuel sandwich adapter to hook up a fuel pressure gauge. You can either get it with a permanent gauge or with a fuel schrader valve for a typical fuel pressure tester.

 

Just checked ... it’s the NATS. Great. Found a local guy who will tune with uprev and bypass the NATS