Recently did an engine swap and now I'm getting a code 16 and the main relay is clicking. Any ideas. I know 16 is fuel injectors and as far as we can tell the circuit is good. Could I have a bad relay, injectors, ECU? I'm stumped. Please help.

 

could be some grounding issues...mine in particular was the one that goes on the thermostat housing...did the same clicking thing your talking about...

 

What does your car do ? Crank over or not even crank at all ? If you cars does not start I am pretty sure you will always throw a code 16 .

 

At first it would start and run but now it won't even turn over.

 

So it just cranks ? I would pull of the fuel hose and see if your getting fuel pressure. Or just swap out the main relay.

 

The first thing i would do is check if your battery has enough power to turn over the engine. My CRX has no spark and no fuel and it turns over every time. If you car does not turn over, it probably needs a better ground. You might try getting a piece of thing wire and ground the engine to the chassis where there isnt paint.

You said the relay was clicking. I had this same thing on my 92 hatch and i replaced the relay and it worked fine. You might wanna try and borrow a relay from someone whose car is working that way you wont buy it and later find out it wasnt the relay.