Members Page/Pete Leh - VEMS wiki www.vems.hu

MembersPage/PeteLeh (2007-02-15 14:47:14)

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

Trigger polarity: I found datasheet of bosch 0261209021 vr sensor, not the same as in Porsche (026121003), but looks just same and has same connectors. According to datasheet connector pin1/3 is N (first half wawe positive when passing magn.object). Pin 3 is shield (as in Porsche). So DME pins 27= Speed sensor+, DME pin 8=speed sensor-, DME pin23= speed sensor shield.

DME pin 25= reference mark sensor+, DME pin 26= Reference mark sensor-, DME pin5= reference mark shield.

All these must be verified by measuring.

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.

Hello! See my page MembersPage/PeteKrgr , I added some information about our Speed and Reference sensors.