Plug And Play Jetronic - VEMS wiki www.vems.hu

PlugAndPlayJetronic (2006-03-16 04:43:08)

I have disassembled a stock LH-jetronic box, And are going to fit it to a volvo 960 16valve turbo.

Read some schematics today, and came up with this table

LH is the Injection box, EZK Ignition box, and TCU is the turbo control unit.. Lots of boxes here!

I have a few questions..

The "Main relay +" is connected to the same relay output as coil, injector+, IAC solenoid+ and a few more places.. Can i use this wire for injector flyback? The flyback definition is very simple: if it's always connected to injector + (no fuse or switch in between, than yes).
(air conditioner) ECC Blocking relay, is used to disable ECC at WOT, also disabled for the first 10 seconds after startup. Pie to implement. Maybe enable ECC after passing a certain RPM for the first time? No.
For the Main Relay coil-, can I have a output that always is driving this after powerup? You can use a wire from VBatt to turn on a FET through a 1k gate resistor. Or the fuelpump relay output.
To make the box as close to plug'n'play as I can, I have to drive all the (HighZ) injectors with one FET, Should i solder the flyback for HighZ or LowZ with 4 injectors in paralell? Definitely low voltage (0.7 + 0.7V) flyback. Or you can just connect several injector outputs in parallel: than flyback can be DR type too: note that with high voltage DD flyback only the lowest voltage (think about tolerances and temperature->opening voltage function: -2mV/K) would carry most of the current! Solder all the flybacks, but not necessary to solder all FETs (but why not solder at least 2 and drive them both - it really costs nothing).

Older LH2.2 pinout (Saab T16 engines)