Non starter - 2003 MK3

[hugh brackenbury]

Hi,
My low mileage 2003 MR2 Roadster no longer starts. It turns over fine but will not start. I cannot hear the fuel pump running with the ignition on, but can't recall if I could hear that before this issue started.

Can anyone advise if you can hear your pump prime up when the ignition is first switched on please?

The car had been running excellently until a few days ago when I pulled out of a junction and it temporarily lost power. Later in the same journey on a dual carriageway at around 60mph, the car stuttered, but then continued home fine, a journey of approx 10 miles. I parked the car up and the next time I tried to start it, 2 days later, it failed to start.

I suspect it's the fuel pump but welcome all views.
Is there a relay control in the pump, and if so where?

Thanks

Hugh

[jimi]

Fuel pump only runs when you crank the engine or the engine is running.

[peteV6R5]

https://www.mr2oc.co.uk/download-cats/d ... 3-bgb.html
the BGB is a good starting point (no pun intended)

pretty sure you have a FP outlet in the diagnostics like the SW20 Mk2
link B+ and FP that you can link to get fuel pump running like in the SW20.
this should help rule out (or rule in fuel pump issues).

[hugh brackenbury]

By way of an update, I can get it to start and run if I connect a 12v supply from the battery directly to the fuel pump. When it is running or cranking, there is 12v at the fuel pump connector as measured by a digital volt meter. If I remove the direct 12v supply and reconnect the fuel pump electrical connector, the engine will stop once the pressurised fuel is consumed. So the system is not sustaining the fuel pump flow when connected to permanent wiring. I have swapped the C/OPN relay with the horn relay as suggested in other posts, to no effect.

Could this be the ECM?

[jimi]

Have you checked for error codes ?

[hugh brackenbury]

Having figured out that actually the C/OPN relay is actually the first relay in from the left, I switched it with the horn relay and bingo, it starts.

For best access to the relays you need to remove the battery

[jimi]

Looks like a duff relay, well done for figuring it out. At least it should be relatively inexpensive to get a replacement relay.