Certified CNG engine
4 cyl 2L PSA engine (Peugeot, Citroen, Suzuki, Fiat)
- turbo: exact type ? ... non variable geometry
- compression: 13.5 (max 10 or 10.5, 13.5 will be a problem)
ECU specs (draft)
- [ETC interface]
- 1 EGT
- 1 knock
- 4 IGBT + 4 logiclevel
- ...
Certification
There are some certification considerations:
R110 (114 pages, my doc is in Hungarian; seems like it is derived from some UN directive) for CNG engine road vehicles... * available in English ?
- Only very small part is for ECU
- p104 4H (after collision, if trigger stops, valve must stop within 5 sec)
- and p113 5O section (ECU-in-cabin operation temperature: -40..+85C)
- these sound easy to maintain with VEMS
Is EMI test needed?
Most likely series resistors will be used, not PWM-ing (with PWM-ing, special harness would be needed to pass certification EMI test, if EMI test needed at all).
The Certification harness might slightly differ from the production harness. Eg.
- contains signal generator for primary trigger
- might be slightly shorter
Why certify ? Third-party certification is good for certification :-)
Trigger
- primary trigger: VR (measured 890 Ohm)
- pattern 60-2 most likely
- secondary trigger: VR
- measured 1500 Ohm
- it's not a problem, but suspicious... why is it VR ? (HALL is more usual for camshaft) What engine was the cylinder head derived from ?
Low Impedance Injectors
3.5 Ohm .. 3.8 Ohm measured, some sites say 1.7 Ohm
- as a verification: 2 injectors in series is 7..7.2 Ohm (so we can say 3.5 Ohm is probably correct)
- Opening time - 2.5 ms
- Operating temperature - 20 ° C (or -40C) to +120 ° C
- '''no injector PWM-ing (because of electronic throttle control, especially for certification harness)
- (6.8 Ohm might be too high to open reliably).
Pressure sensors
MAP sensor on "air-side"
- BOSCH 10-07-133-FL1 816 0261230042
- is this in manifold ?
- CNG pressure senzor: BOSCH 0 261 230 145
- 0-5V analog signal ?
- What is the CNG pressure regulated or pressure compensation needed ?
- What is CNG pressure ? (or what is the pressure range ?)
Harness for certification
- 1 or 4 injectors ?
- signal generator
- can TUV apply 13.5V (12..14V) DC supply
- or should we include a 230V => 12V supply with the test setup ?
Ignition
- 4 COP
- active or passive ?
- resistance measured ?
Exhaust measurement
These are easy:
- CO
- CxHx
- O2
- NOx
- CH4
Installer should make a proposal (netlist of connections) and submit for review
- see ETC (above) (gázpedál+pillangó szelep)
- TPS (gáz szenzor)
- TPS2
- PPS
- PPS2
- injectors with series power resistors (gázszelep)
- alsó felső holtponti érzékelő
- MAT (levegő szenzor)
- CLT (víz hőmérséklet)
- LSU4 (oxigén szenzor)
- ignition (above) (gyújtó tekercsek)