Just having a nice miata drive enjoying the warm thanksgiving weather; pulling up to a stop light and the wideband goes full lean. Okay.... Stop at a light. Dead, and that was it. God dammit.

After some thinking; DW300 pump. I cant hear it prime or run so obviously that's my issue.

12V to the pump alone and pump runs. 12V to the connector ontop of the pump and pump runs. Jumping FP to ground I hear the relay click as well as I get 12V at the connector plug ontop of the fuel pump (red/blue to ground).

Any ideas? Im dumbfounded how 12V to the connnector runs it and I get 12V at the connector plug but somehow it still doesnt go.

 

I had a very similar thing happen with my car and a DW300. It ended up being the fuel pump relay under the dash. I know you said you heard the relay click, so maybe that's not helpful or relevant to your situation, but the circumstances seemed similar enough I thought I'd chime in. At least that's an easy and cheap thing to try if you're at the point of throwing parts at it.

 

I have 2 other na6 chassis cars at my disposable. Already swapped the FP relay with a working one to try. Exact same outcome but thanks for the ideal.

 

Sounds like a possible internal break in the wire somewhere near the plug. The wire makes a connection internally when you have it lifted into a different position to test it with the volt meter, but when it's back in the same old position where it's plugged into the FP the wire no longer has continuity.

 

I've been pondering this too. I'm going to try to run 12V to the top of the tank and see if that runs it in position to eliminate that part of it.

Also I'm going to try to do a continuity test of the red/blue wire from the FP relay to the connector at the drivers footwell and also from that same connector to the plug for the top of the tank and try and narrow down the area of my problem.

 

With the tank back in place, 12V to the white plug on the sending unit I couldn't get it to run. Must be a bad wire within the sending unit that changes when moved as mentioned.

Going to try a 1.6 unit from one of the other miatas to confirm and until i can get a 1.8 unit