The first topic is here: http://rusefi.com/forum/viewtopic.php?f=2&t=1245
In few words: I have Citroen C5 2.0 HPi (direct injection). I would like to let rusEfi control the engine. Main reasons are:
- too expensive engine for support - not well designed high pressure fuel pump which fails and costs a lot - possible elimination of the high pressure fuel pump after failure or in future experiments;
- too delicate for normal LPG injection kit. 1st these LPG kits are expensive. 2nd they rely on tight communication with the factory ECU in order to keep the fuel mixture precise. Almost no DI LPG ECU suitable for this engine;
- Faulty wideband O2 sensor - while it sounds like a great toy to play with, it is also expensive. I plan to cut the engine from operating in lean mode and to use ordinary O2 sensor. Also the engine burns some oil and this means that any O2 sensor installed will break.
- LPG would lead to gasiline injectors burnout. Therefore a short amounts of gasoline should be injected together or in separate cycles in order to keep them in good condition.
- in the future, if the high pressure pump or any of the DI injectors fails I can mount single or four ordinary fuel injectors at the manifold and convert the engine to normal port injected. This may be done also for solving cold start problems typical to this type of engine.
- and beyond that - if it happens to live - I would like to experiment with LPG direct injection, probably I'll mount port injector(s) for petrol and feed the installed fuel rail with LPG.
So you can see there are several configurations of the fuel management that I would like to play with.
Table of contents (to be filled on each successful step):
1. First steps - this posts - shows some oscillograms of the fuel injectors.
(next)
- driving circuity (not yet completed)
- ETB - throttle body motor control (not yet completed)
But first, let me write all the periphery connected to the factory ECU with my view of what should be driven by rusEfi, what can or should be left to the factory ECU and what should be "emulated" to prevent the factory ECU from inappropriate work.
--- to be disconnected/proxied from the factory ECU ---
Fuel pump
Injectors (x4/x8)
Input Air Temperature (IAT)
Engine coolant temperature (ECT) sensor
Fuel rail pressure (FRP) sensor
Knock sensor (KS)
Manifold absolute pressure (MAP)
Engine coolant blower motor
Accelerator pedal position sensor (APP)
Throttle body motor
Throttle motor position sensor
Crankshaft position sensor (CKP)
Camshaft position sensor (CMP)
Ignition coil (x4, each cylinder)
Camshaft position actuator
Fuel pressure regulator control solenoid
--- under consideration ---
Pre-cat (wideband) O2 sensor (5-wire?)
Post-cat (narrowband) O2 sensor
Exhaust gas temperature sensor 1
Exhaust gas temperature sensor 2
Exhaust gas recirculation (EGR) valve position sensor
EGR solenoid
Evaporative emission (EVAP) canister purge valve - ???
--- not to be touched ---
Brake system vacuum sensor - TO BE TESTED AFTER rusEfi installation! Incl oil pressure sensor, etc...
ABS conntrol module
AC refrigerant pressure sensor
Power steering pressure switch (PSP)
Clutch Pedal Position (CPP) switch
Cruise Control Brake pedal switch
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Today I did a little research on how the ECU behaves. I took the signals from the CMP (Camshaft Position Sensor), CKP (Crankshaft Position Sensor) and the voltage over 1st cylinder's injector.
First of all, yes, this is true DI engine. It has a high pressure pump and drives the injectors with high positive and negative voltage in order to open and close them.
The injector timing is divided in several steps as follows (engine idling):
1. 400 us (micro-second) "start-up" time with 12 V DC voltage.
2. 600 us period follows after that which is PWM modulated +12V. It looks like the duty cycle is higher in the beginning and lower in the end of the period, but I can't guarantee it.
3. 200 us high voltage (80 V DC) (opening) period.
4. 200 us +12 V DC period (probably keeps the injector open).
5. 30 us period follows with -80 V DC negative (closing) voltage.
------- till now the period was fixed. Remember that these readings were made on idling engine w/o any load (headlights, AC, fan, etc.)
The 6th period changes with each revolution and the engine load (even when idling). Keep in mind that the condition of the injectors is unknown, also the pre-cat O2 sensor is broken (wideband).
6. 100 us period with 0V (nothing happens). It may continue with 0V followed by second (-80) negative closing peak which ends the injector's cycle OR it may put some 12 V PWM modulated (it was always changing when I took the scope shots) after which follows the second -80 closing peak.
You can see a video https://youtu.be/xZYNPauRSJ0
Please make note of the ugly noise which disappears when the injector time decreases. I guess this is the moment when the ECU switches the operating modes (normal mixture / lean mixture). In normal mode the gasoline is injected in the 1st stroke and in lean burning mode the fuel is injected about the end of the 2nd stroke.
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And a scope shot of the camshaft and the crankshaft position sensors: I'm not sure about the timing of the camshaft sensor - should it coincide with the crankshaft? I guess there is difference since I think the engine has something like a camshaft actuator...
![Rolling Eyes :roll:](./images/smilies/icon_rolleyes.gif)
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I think there is a chance for rusEfi to be used, but some hardware should be made to drive the injectors...