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.
- 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.
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)
- 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)
- 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