If it's the CAS you'll also not be getting any spark so if you have someone to help, you can pull a coil pack and test for spark while they crank. No spark, no fuel, you've nailed your issue; the ECU isn't getting a signal from the CAS for whatever reason.
I looked over all the wires from the cas and none of them looked corroded or bad but I took a multimeter to it and wasn't getting anything but I could've tested it wrong. I have spark i just checked it but still no fuel. I'll run codes here in a bit and keep you posted, thankyou so much for your help by the way i appreciate it.NukeKS14 wrote: ↑Mon May 25, 2020 7:44 pmIf it's the CAS you'll also not be getting any spark so if you have someone to help, you can pull a coil pack and test for spark while they crank. No spark, no fuel, you've nailed your issue; the ECU isn't getting a signal from the CAS for whatever reason.
Here's a link to the English-translated FSM from our own site;
https://www.nicoclub.com/service-manual ... R20DET.pdf
It's that easy. You're simultaneously testing the CAS and wiring to the ECU here. If you don't get any response from the injectors, it could be bad CAS or wiring. How did you test the wiring between the CAS and ECU? What do you mean by 'seems fine'?
Also, try pulling codes from the ECU and let us know what you're getting. The computer will tell you what it thinks is wrong. The procedure for this begins on page EC-50 of the previous link.
Okay so I just tried checking the resistance between the ecu and the cas harness. I tried all wires on the harness and i tried pins #30 and #40 on the ecu but there was no resistance. Was I doing it wrong or is that the issue?NukeKS14 wrote: ↑Wed May 27, 2020 5:47 pmvisual inspection almost never tells you anything. to test the harness you need to disconnect the battery AND the ECU, and check resistance between the component end and the ECU. NEVER do continuity checks on a live circuit. low resistance (<100 ohm at absolute worst, ideally <10) tells you the wire is good from the component to the ECU. It's important to move the harness around while you're checking to simulate engine movement and vibration. A wire can become brittle and break inside the insulation, making intermittent contact.
So the way the Nissan ECUs work is by a ground switching approach. constant voltage is supplied to the controlling elements (coils, injectors, solenoids, starter, etc...) and the ECU operates them by completing their circuit path to ground.
Next thing I'd do is turn the ignition key to the on position and check voltage at the red wire on the injector clips to ground. You SHOULD be seeing near 12v. The injectors have a common 12v supply so if you're finding it on the first one it's on the rest of them. don't test BETWEEN the wires. Test red wire to ground. If you're not getting that, the second picture shows the path from the ignition to injectors. Something is broken faulted or disconnected between there and the ignition. no fuses between the ignition and the injectors. Wouldnt hurt to double check that 30A ign fuse though.
Sorry for making this difficult im new to this but i'm a little confused because the ecu pinout sheet you sent doesn't match my ecu but i tried anyways and I got the same result. Heres a pic of my ecu and my cas plug.NukeKS14 wrote: ↑Wed May 27, 2020 8:31 pm: Wrong pins.
White wire on cas harness (pin 4) goes to pin 51 on the ecu
The black wire on the cas harness next to the white one (pin 3) goes to pin 42 on the ecu.
Ec-109 for the cas wiring
The white/black wire at the cas plug (pin 1) is your 12v in.
If youre getting spark the cas is working. Did you pull codes before disconnecting the battery? If not theyre gone. They live in the volatile memory.
Also, overload means infinite resistance. Opposite of no resistance.
oh no man it's alright you've already done so much to help me. It's weird i looked up all the sr20det pinouts and it matches the one for the kouki but im running a blacktop zenki