Crank but no start, but can cold start (then die) with jump starter

[MrGoatNipples]

ENGINE/DRIVABILITY

Year/Make/Model: 2006 Mazdaspeed 6
Mileage: 245,000 kms
Location: Brisbane, Australia
Concern: crank, no start, wiring harness in bad condition as well as PCM/ECU which was submerged in water from leaking A/C condenser line
DTC's: PO335 (on OBD II), but COBB Accessport v3 shows no DTCs
Modifications: Corksport hpfp internals, Corksport CST4, front mount intercooler
ECU/Tuning Software: Factory ECU, COBB Accessport v3
Tuner: Unsure
Is the concern intermittent? No
Can you duplicate the concern? Yes (I believe)
Recent Repairs: New crank angle sensor, replaced battery
Correction: Inspected crank angle sensor connector and tested voltage (reading 8v), also inspected the PCM and ABS modules which had some discolouration on the circuit board.


Essentially, the car turns over and starts with a jumper on the first go, but fails during subsequent attempts. The wiring harness is in all-around bad shape from the previous owner's attempts at modifying the car, and the passenger side floor was flooded with A/C condensation water for a month which I believe has damaged the ECU. When I took it to my tuner (East Coast Customs Brisbane), they mentioned it was throwing the PO335 DTC which I have confirmed, so they replaced the crank angle sensor but cannot resolve the crank no start issue. I used a multimeter which read 8v from the connector to the crank angle sensor which I am unsure of is adequate or not.

All in all, I would just like some advice on what the next steps should be. At this stage, I am lead to think that obtaining a new engine loom (I don't know which specific wiring harness I need to be replacing to address this issue), and a new PCM/ECU and ABS module (since that would have suffered flood damage too).

Apologies if I have not provided enough information as I am new to maintaining/working on cars, and from what I'm quickly learning, Mazdaspeeds are pretty notorious in this regard.

 

[Rokusek]

Check all your grounds, if that doesn't work, replace the ecu.

 

[Enki]

Also, check which direction the crank angle sensor is installed, and maybe check timing if you can. It's possible to install the sensor improperly.

 

[Easter Bunny]

You said you put in a new battery are you sure it also isn't bad?

Try unplugging the ECU cleaning the connectors if necessary and plugging it back in

You aren't going to find a new wiring harness you will have to pull one off a wrecked car or repair the one you have

 

[Rokusek]

You aren't going to find a new wiring harness you will have to pull one off a wrecked car or repair the one you have

I wish you god luck with it being any good. I personally am 15 used harnesses in to my search and have only found 2 to that are good. Need to find someone doing a part out who's going to care about taking the harness off the car.

Repair isn't impossible either.