Golf Cl 91- Engine AGG 2.0 8v write-up
MORE TO COME
- ECU v3.6 2+6 Pre-built V3harness
- Ported polished head
- Catcams 266 Soon Catcams adjustable Cam sprocet CCR3232
- 1.8t injectors # 0280156061
- 16v fuelpump
some stock sensors from 97 mk3 Gti
- MAT (G72)# 028 906 081 - Changed to VEMS MAT sensor
- Coolant (G62)# 357 919 501A - Changed to OEM Golf Blue 2 pin sensor
- knocksensor Volvo 940 # 0 261 231 006 Not configurated
- primtrig: HALL (G28) # 037906433A 60-2 OEM wheel
- HALL +5V supply from EC36/pin28
- Stock throttle body (J338) PIN 4-5&7(see picture) (using Vems builtin idle)
- Wideband LSU4.2
- fuelpump Trigger OEM Fusebox relay G1/03
Wasted spark Coil- Bosch motorsport # 221 503 407
PIN Outs 2 + 6
Tachmod golf Mk2 - 2x1N4007 Diod
+5V supply for BT RS232 adapter
- measure your RS232 DSUB9 female on v3harness between pin9 and pin5
- It is better to use DSUB9/pin9 for +5V than the USB (USB connectors are rather fragile)
- Q Added +5v to DSUB9/pin9
- but when android connects, fuel pump is turned on and will not stop
- +5V from where ? EC36/28 ?
- is the DSUB9/pin5 GND connected from EC18/17 ? NO, Connected to main ground like prebuilt harness, as before I added +5v. I did measure, EC18/17 is internally connected in ECU to EC36/26. Should i change ground to EC18/17 pin?
- Can you measure with DVM that EC18/17 is internally connected in ECU to EC36/26 ? (been the standard for quite some time, but if the ECU has dual WBO2, or an old ECU, then EC18/17 is not grounded internally so GND connection from EC36/26 must be maintained externally)
- Do you have some other +5V source to try? (eg. a wired-in 12V=>5V regulator, or cut the USB cable from a failed mouse, find GND and +5V, take care of polarity, and supply from a cigarlighter USB socket)
- fuel pump is turned on when pulses detected on EC36/pin26 primary trigger.
- for VR sensor (depending on LM1815 adaptive threshold setup), even low amplitude (eg. 140mV to allow starting in winter with depleted battery) pulses can trigger.
- however, for HALL (which provides <0.5V and >4V signal), much larger swings needed, and definitely grounds should be checked
- just the android serial stream should NOT cause fuel pump to turn on, so definitely find some GND or +5V disturbance to HALL sensor.
- Although normally should not be needed, might help: an added 47uF or 100uF (min 10V but rather 16V or 25V electrolitic) capacitor in DSUB9 housing between DSUB9/pin5 (-) and DSUB9/pin9 (+5V), take care of polarity
A)YES +5v from EC36/28
NO, Connected to main ground like prebuilt harness, as before I added +5v.
- I did measure, EC18/17 is internally connected in ECU to EC36/26.
- Should I change DSUB9 ground to EC18/17 pin?
- theoretically RS232 GND should be fine either EC36/26 or EC18/17 (as they are confirmed connected inside the ECU)
ECU ground Should be OK?
What if you make a DSUB9 connection to the notebook with ONLY DSUB9/pin5 GND ? (no pin2/pin3 communications).
- Does the notebook disturb the engine GND even than ?
- what if notebook is powered from battery, not the mains ?
- sounds like the notebook ground injects surprising level of noise into the engine GND (or perhaps into +5V or HALL signal, but that is less likely)
- does the engine have any other connection to mains ? Like a charger attached ? ("ground loop")
- do you have scope to measure these ?
- I did notice I have a bad battery, measured 10,66 volt only, might be causing the problem? buying a new and report back later going away for 1,5 weeks