Injector assistance with Z32 Type 2 running RB25DET Neo

[Akshunhiro]

Hey all, finally got my engine in but now trying to fiddle with the base map to get it to idle correctly.

I ordered a Type 2 a while ago to run a S2 RB25 but ended up upgrading to a Neo and it was easier to run the S2 R33 loom rather than adapt the 34 engine loom to the S2 R33 body loom.

So here's where I'm at. All ECU's mods have been done to run the S2 RB25 but engine doesn't want to idle. I figure it's likely due to injectors.

Had a friend come out to play with k constant and latency and we got it to purr but by the time we got it right, it was warmed up so couldn't really check cold start. I'd hate to ask him to come back out since he's not really close.

I've tried running it again and it doesn't want to idle. It seems like it's getting way too much fuel. Is anyone able to tell me the values for k constant and latency with the stock Neo top feed injectors?

I'd like to get the values punched in so cold start will be happy. Here's what I've got;

Z32 ECU with Type 2, S2 RB25 base map (mods done as per v7, haven't played with knock sensors as documented in v8)
Z32 MAF
S2 R33 engine loom
S2 R33 throttle body and TPS (TPS has been adjusted, .45v at idle)
Spliced in Neo VTC solenoid and idle control valve
Stock R34 GT-T top feed injectors (I can't find solid info to confirm size)
Stock FPR
Aeromotive Stealth in-tank pump 340lph (earth mod to give full power and not 9v when off throttle)

If I can obtain stock values for R34 then I'm sure it will be happy but also need to cater for MAF since the 34 can run a Type 4 with stock MAF.

Any input appreciated!

[Matt]

Z32 injectors 370CC (K=288) > R34 injectors 380CC (K=280)

There should be minimal change to the K constant. If you are using the ECR33_for_RB25 BIN file from the ROM pack, make sure Z32 MAF is selected and K = 280 to start with. 750uS latency should be fine also

[Akshunhiro]

Thanks Matt. Got it sorted and it seems to be happy now.

Turns out R34 MAF was selected. Changed this and set the k constant to 280 but couldn't get it to run with latency less than 1200.

[Akshunhiro]

Just one other query related to wiring. Just wanted to confirm whether I should get an earth where the oxygen sensor is. I think feedback was disabled as my o2 sensor may be shot which was causing the car to hunt when at/close to operating temp but I thought I would still see an earth at the plug unless it's switch by the ECU.

I checked continuity between the ECU and plug and all check out, I am getting +12v too but no ground. Wondering whether this is normal, an ECU problem or whether I should just go ahead and earth it to the chassis.

[Matt]

At the O2 sensor there should be three wires. Red (12V), Black (GROUND) and white shielded (signal 0 - 1 volts)

At the ECU the O2 sensor pin 29 should have the white shielded wire going into it and read 0-1 volts as reported same as nistune when testing with a meter.

With Z32 ECU there is also pin 55 for the second sensor, which should be connected internally to pin 29 (both sensor inputs together) so that they read the same (LHS and RHS) inside Nistune