yes it's soldered, and the wires and hoses are fuel rated.
But, indeed I doubt that the heat shrink is not... Can it melt inside the tank ? I will immerge some pieces of the remaining heat shrink in a glass of petrol and I'll see what happen in the upcoming months

anyway, I just tested continuity between the pin at the ECU harness and at the fuel pump relay, and it's OK.
So, I should check the wire from the relay to the power source... according to the schema below, it's probably connected in the small relay box near the shock tower... B/LG wire. But when I did the rewire last week, I didn't notice anything wrong there.
I should maybe also try to replace the relay anyway... who knows...

 

Yeah I had standard heat shrink pass a gas test in winter and then checked tank in summer and they were getting weird. Nylon, viton, teflon are all great for fuel.

 

Ok, I continued the troubleshooting.
I've got good power (12V) at the relay, and the continuity to the ECU harness is OK
The relay is good (I checked 2 of them multiple times)
So now, it really looks like it's the ECU the culprit.
I may try what happen with the OEM ecu, but, I don't know if it's a good idea to drive it hard with my mods (IC, DP, HighFlowcat and CB).. I don't even know if the stock ECU can deal with the air pump disconnected (and aws, double throttle, etc) and a simplified ratnest ....
I will also open the PFC and check if everything's ok in it...

 

Don't know about the ECU. Didn't you say you bypassed the relay and got 12v at the pump?

 

Yes, I did. It was a test in order to troubleshoot where the problem come from.
I just want it to work as it should, with the fuel pump relay (speed) and the resistor at low load.

 

Getting specific, exactly what did you bypass. The main relay, the hi speed relay, both? And where exactly did you connect your bypass?

 

I bypassed the FP speed relay (like in the photo below) to understand why I had always a low voltage at the pump. So now I know it's because this relay never activates. The ECU never ground it.

 

Without getting into my car and looking at that relay, i'm guessing you made the connection between the L/R and W/R wires circled. If so, you actually bypassed the Fuel Pump Resistor which in essence replicates the control system for heavy load that activates full power to the pump (because it's not going through the resister). If you are positive the "speed" relay is good, it very well could be the ECU which controls both pump relays. You may want to check resistance in your conductors in that entire circuit (especially the circuit that controls the high speed relay) to include grounds.

 

Yes, this is what I did, and checked resistance, which is fine. That's why I believe it's the ECU that doesn't trigger the speed relay.

 

If you are double extra certain positive the relay and wiring and grounds are good, then it's probably the ECU. Can you get your hands on another one

 

I'm trying to.
I have a oem spare one in my garage, but I really don't know if it's safe to use it with all my mods... IC, DP, HighFlowcat and CB).. air pump disconnected (and aws, double throttle, etc) and a simplified ratnest ....

 

you only need to boost it to 1psi, not even full throttle...

 

yep, I will try to do it gently !
thx

 

You may not need to change the ECU. Check the voltage at the speed relay from the ECU. It should read ~12v at "low speed". If you're not getting 12v. Check the resistance of that wire back to the ECU (1K). If it's in spec, then it's definitely the ECU (you could double check the wiring by seeing if you are getting 12v directly at the 1K terminal of the ECU). If it's the ECU, it's your decision what to do. I believe bypassing the FP resister has been done as a "performance" mod, i.e. running the pump at high speed all the time (there should be numerous threads addressing pros/cons).

 

that, and actually if you were lazy like me, you could start the engine, bring it up to like ~2k rpm, and blow into the map sensor hose and see if the relay switches.