Porsche 944 turbo/Injector & Flyback ? (v3.x serialnr 731)
- Originally Porsche has injectors 1&2 and 3&4 connected parallel.
- Ok to use same connection with VEMS
If using lowZ injectors, you must either
- NOT have TS-diode in flyback path (this way you can do PWM-ing)
- or have power resistors (6.8 Ohm 15..50W power resistors) in series with each injector (in this case you must NOT do PWM-ing)
Transient diode is only built inside VEMS if you explicitely request so.
- If you request powerflyback, you get powerflyback.
- If you request low voltage flyback, you get low voltage flyback (this is easiest to measure: DVM diode mode shows appr 800..1200 mV between pin23 (cathode negative) and any of the 8 injector outputs (anode, positive)
Making Plug and Play motronic
Old motronic box gave 35 pin connector.
Make sure to follow the rules, most importantly the
- grounding
- and flyback rules.
This is very important. Read MembersPage/PhatBob/UserGuide
You can easily damage stuff if not following instructions, which really requires attention especially with a PNP install. The grounds will surely not be connected as required until you do it yourself.
Trigger
- Polarity
- does anybody know polarity of sensors according to DME connector pins?
- measure with DVM, 200mV DC mode. If your wheel has normal shape (missing tooth), than signel should be +few mV when you move ferrous metal (iron) towards the sensor, and -few mV when you move it away. The reading shows up for a very short time only (while the sensor actually sees the movement)
- Chancing crank home sensor polarity: On Audi trigger arrangement the polarity of crank home sensor should be reversed, same with porsche trigger (132 tooth+crank home)? Do NOT count on this. Do same DVM DC mV measurement for both VR sensors
Trigger sensor shieldings:
- connect to ground
- more precisely: connect to ground at the ECU (EC36pin26 GND)
Nothing conflicting there.