I had my s4turbo motor swapped out by my brother and a friend of his and they were supposed to swap a jdm s5 motor into it with the whole correct wiring harness and everything. I ended up taking the car back 18months later and pretty much everything was swapped over but it was taking them awhile to complete it. When I got the car I got the radiator welded in ran new fuel lines and hit the starter. The motor ran but sounded like crap like maybe it was running on one rotor. We checked all the ignition stuff but everything fired correctly. We went to check the fuel next to see if maybe an injector was bad. It turned out that only one injector was firing. Any advice or ideas on what could cause this? Should I check the ecu first, anyway I could borrow a ecu to see if mine is bad

 

Check the connectors going to the injectors if they're broken or burnt out. It has happen to me too. Its a cheap and easy fix if this is it. Also check compression may never know. Or if u switched the connectors to the injectors by mistake

 

well i unplugged my fuel injectors and unplugged the fuel pump and cranked the motor over so could check the injector wires and only the first wire gave any signal

 

AAre the pins in the other 3 connectors to the injectors loose, burnt, or broken? If so replace the connector.

Or Splice in to the wire b4 it goes to the connector too see if its getting power. If getting power, replace the connector. If not well then u may have to start searching for a short. If nothing found I would suspect the ecu.