After some consideration of my options, I'm almost set on going with VEMS for engine management. Anything that's cheaper is far less intelligent, anything that's more intelligent is also more expensive.
The car is an '89 S13 200SX w/ a built CA18DET engine. 1809ccm, 4 cyl, turbocharged, intercooled, multipoint sequential FI, COP ignition.
Aligning VEMS with the engine:
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
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 (not in this order, TBC)
- (I don't yet know which window corresponds to which cylinder)
- VEMS
- using the same CAS with the "nissan 360 degree secondary trigger" option
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
Knock sensor
- Original
- 1 channel, piezo type, mounted between #2 and #3, shielding grounded to ECU ground
- VEMS
- using the same
O2 sensor
- Original
- N/A, stock narrowband removed, Bosch 4.x installed (probably 4.2, TBC)
- VEMS
- using the Bosch 4.x WBO2
MAIN OUTPUTS
Ignition
- Original
- Individual coil on plug, ECU outputs logic 5V signals for each cyl.
- 5V signals go to power transistors mounted in engine bay, these drive the individual coils
- Individual coil on plug, ECU outputs logic 5V signals for each cyl.
- VEMS
- using the same, putting out 5V logic signals
- Q: how difficult to convert the IGBTs afterwards, if needed? (not likely, but still)
Injection
- Original
- lowZ injectors with dropping resistors mount in engine bay
- VEMS
- need possibility to drive either highZ or lowZ-s injectors, so "active flyback" option required
- Q: do low-Z injectors still need dropping resistors?
Idle Control
- Original
- no idea, probably the same as any other Japanese vehicle from the same era, 2pin terminal, 12V PWM
- VEMS
- using the same
Fuel pump control
- Original
- low side switch, probably, TBC
- VEMS
- using the same
- Q: any "modern" features, like 6V operation, PWM closed loop w/ fuel press. sensor?
Questions so far:
Flyback type: which one for lowZ, lowZ+R, HighZ?
ECT: for 2wire ECT, where is the 2nd wire connected? Ground?
Triggers: what is primary/secondary?
Auxiliary outputs
water pump PWM control for SSR (future)
[NOT YET FINISHED]