MembersPage/BlownHemi/PrepMainInputs (2017-07-19 06:22:00)
MAIN INPUTS

Air metering

Original
MAF
VEMS
4bar MAP + IAT (already have both)
MAP will be mounted externally, close to the IM, shortest possible tubing
5V supply comes from the ECU
IAT is a BMW type, res./temp diagram TBC
Wiring changes - MAF
Cut off MAF at the pigtail, it's 3 wires (12V, GND, signal). Use these for the MAP sensor, which also takes 3 wires (5V, GND, signal).
Wiring changes - IAT
Need to look for a suitable wire that will be freed up, and goes to the throttle body area, where the IAT will be located.
  • 1 or 2 wires? Ground wire could be spliced into the ECT/TPS ground B wire, which is right there. Only 1 additional wire needed then.
  • Idle switch? 2 wires from ECU, and idle switch is not used in VEMS, but TBC.

Crank angle, cylinder pos.

Original
mounted on EX cam, disc has two concentric rings for two optical pickups with OC outputs
(pulled on up ECU side)
ca18detCas.jpg
Outer ring has 360 slits
Inner ring has 4 windows w/ lengths in slits: 16, 12, 8, 4
CHECKED no. of degree pulses for Window slits High/Low (H L H L H L H L) 16 74 12 78 8 82 4 86
CHECKED 16 pulse window corresponds to Cyl 1. According to a few Internet sources, Rising edge of 16-slit window is 60 BTDC. Which sounds logical.
For primary trigger, will either use:
  • Rising edge w/60 BTDC
  • Falling edge w/28 BTDC (window length is 16 sectrig pulses, that's 32 crank degrees)
Secondary trigger will use Nissan special trigger option, sync Cyl#1 to Window longer than 13 sectrigger pulses ("Ignore pulses shorter than" option)
cas4.jpg
VEMS
using the same CAS with the "nissan 360 degree secondary trigger" option
Wiring changes
The TDC (inner ring) and the angle (outer ring) signals are both wired double into the ECU, on pins 41+51, and 42+52, respectively. Probably a good idea to solder these together, before crimping it into a connector.
JDM swap guys and RHD M/T guys should check their wiring/colors on FSM page EF&EC - 82. It's a bit unclear, the TDC and angle signal has the same wire color (G/B). Label them before you cut.

Engine coolant temperature

Original
NTC regular type, 2.5kOhms at 20*C, 300Ohms at 80*C
VEMS
using the same

Throttle position sensor/switches

Original
Idle switch, closed when pedal released
TPS ~1kOhms - ~9kOhms for fully released, fully pressed, respectively
VEMS
using the same, except idle switch is not normally considered (although it can be connected to a free analog input of course). Mixing in idle switch (pulling to GND, but through 10..20k) into TPS signal (for a voltage "step") is superfluous and should not be justified, TPS has all the information without this anyway.

Knock sensor

Original
1 channel, piezo type, mounted between #2 and #3, shielding grounded to ECU ground, near ECU
VEMS
using the same

O2 sensor

Original
N/A, stock narrowband removed, Bosch 4.x installed
TBC 4.2 or 4.9
TBC for any special requirements for an extension cable, twisting, shielding, etc., or just simple wiring
VEMS
using the Bosch 4.x WBO2 directly