I developed a Plug and Play solution via adapter harness for Porsche 944 Turbo aka 951. It uses two ECU's, DME (Motronic 1.0) controls fuel and spark, the other (KLR) listens for knock and controls boost pressure.
All the necessary signals are available with stock harness, including healthy grounds. Here are pinouts:
Here's my solution:
The car has 132+1 auditrigger crank trigger without cam sync, it uses distributor. Injectors are connected in pairs.
Now here's my issue.
I tested the setup on the running car and all sensors seemed to work except I did not get rpm signal. After disabling secondary trigger rpm showed which means tooth wheel reads fine. Secondary trigger is not visible in triggerlog also.
I used latest VEMStune and chose 4cyl_Porsche_132+1 configlet with divby11.
I configured secondary trigger per http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FInputTriggerHardWare
- Added 2nd LM1815
- SJ7 connected
- Routed wire to EC36 pin13 and left cam hall inverter bridge disconnected. Tried with connected, still nothing.
I also tried to reverse 2nd VR wires, no effect.
- beware, that with the "camHALL inverter" setup, EC36/13 sectrig HALL input must be connected to a sensor or pulled to constant ground so that the secondary trigger VR LM1815 signal can reach the processor
- without camHALL inverter (NPN not solder, just a shorting blob instead) the EC36/13 can be left open (internally pulled up to 5V)
- measure the +5V supply of the LM1815, just in case
EDIT: Trigger signal issue was solved, a missing pullup on the bottom of the board.
Here's vemscfg: https://www.upload.ee/files/4472538/944_Turbo_Stock.vemscfg.html
Trying to get the factory in-dash boost gauge to work. It appears to be using 0-4.5v signal from the KLR ECU and is linear voltage. 1 bar is 0.45v. Main goal is to make the gauge show 1 bar as real 1 bar not absolute like in factory ECU.
Q: Is it possible to use VEMS internal MAP sensor signal for this through some resistors or something?
A: Already answered here, we have a dedicated function for this called boost gauge: http://www.vemssupport.com/forum/index.php/topic,2391.0.html
Here's a topic in Rennlist about the boost gauge and how one guy got it to work as standalone: http://rennlist.com/forums/944-turbo-and-turbo-s-forum/434511-q-for-electronics-techs-boost-gauge-control-2.html