Mazda MX-5 Miata banner
21 - 22 of 22 Posts

·
Registered
VVT swapped NA & TD04 turbo NB
Joined
·
413 Posts
Discussion Starter · #21 ·
First thought is the 2 seconds priming will pressurise the fuel rail and that probably means there's enough fuel to start the car. That could be all the fuel you're getting. So it may be the pulsing effect you saw on that ground pin while running isn't enough to drive the FP relay. I think it needs to be established if that's normal. It sounds as if there's some kind of PWM drive signal on that pin there when perhaps it ought to be a solid ground. MSEXTRA forum is where I would go to ask.
I had one final test to do yesterday before Tom went off to speak to BOFI, MSExtra people and eventually the guy that engine swapped this car.......

I was going to test to see if the fuel pump was running during cranking and the car fired right up, 3 times in fact.

I tried multiple times the day before and it definitely didn't work when the pump only primed for 2s but it did work AFTER when I put the pump back to permanent ground. All while the grounding was doing what it was supposed to on the board.
The only explanation I have is that the the plugs were wet and it was a coincidence that I managed to get it to fire twice (it did splutter into life both times on perma-ground suggestion flooding was possible cause) but still doesn't explain the PWM effect on the grounding on the board. My tune is set up in switched mode not PWM, tried to switch to PWM and back to switched but it had no effect - which is most curious.
 
21 - 22 of 22 Posts
Top