Hi,
just to keep it alive, more news after refitting everything to place.
First of all I discovered the mysterious relay+fuses are part of the front screen heater circuit. I picked it on a picture in the manual and then confirmed by operating the switch and feeling the relay vibrating. It could be somehow related to Efi as the ECU senses the ON/OFF of this relay to put up RMP and compensate for electrical load.
Presently the fuses are removed so the relay can be switched + the switch light comes on, but there is no load.
However, when everything was back I started the engine again and…surprise… back to 1500 RPM idle. No oscillations but high RPM. Waited until engine reached running temp but idle remained at 1500. Considering that the relay was a potential source of troubles I tried switching on and off. While in ON there was no increase in RPM, and when in OFF in 2-3 secs it went from 1500 to 1300, I repeated the on/off and it went down to 1100, going to 900 at third attempt. 4th and 5th attempts didn’t decrease any further.
I switched off then restarted and this time it started idling immediately at 900-1000 and there it stayed with no surging, no misfiring, etc.
Will see when it’s cold again if the pattern repeats, and if so I will try removing the relay and see if 1) it cures the symptom or 2) the switch itself acts upon idle, which implies the timer unit of the heater is involved rather than the relay.
It was when I tried to understand if actual wiring is as expected from diagrams that I discovered the front screen heater has a timer unit. This what the manual says:
“……HEATED FRONT SCREEN
The heated front screen will operate when the
switch is operated with engine running. The timer
unit, see Relays-identification, will provide a preset
time cycle of 7 112 minutes + 20%.
Switching off the ignition, or further operation of
the heated front screen switch during the cycle will
switch off the screen and cancel, reset and switch
off the timer unit……”
Anybody knows what is the correct time? It obviously cannot be 7112, nor it can be 7 or 112. It could be 7/12 and a bad scan of the page on paper....
As far as I could inspect wiring is ok but... anybody knows why the oil pressure switch feeds into the front screen timer unit (as per diagram on manual)?
Sometimes the logic behind these things is really hard to pick up…..
Many thanks
Ciao
Adri
just to keep it alive, more news after refitting everything to place.
First of all I discovered the mysterious relay+fuses are part of the front screen heater circuit. I picked it on a picture in the manual and then confirmed by operating the switch and feeling the relay vibrating. It could be somehow related to Efi as the ECU senses the ON/OFF of this relay to put up RMP and compensate for electrical load.
Presently the fuses are removed so the relay can be switched + the switch light comes on, but there is no load.
However, when everything was back I started the engine again and…surprise… back to 1500 RPM idle. No oscillations but high RPM. Waited until engine reached running temp but idle remained at 1500. Considering that the relay was a potential source of troubles I tried switching on and off. While in ON there was no increase in RPM, and when in OFF in 2-3 secs it went from 1500 to 1300, I repeated the on/off and it went down to 1100, going to 900 at third attempt. 4th and 5th attempts didn’t decrease any further.
I switched off then restarted and this time it started idling immediately at 900-1000 and there it stayed with no surging, no misfiring, etc.
Will see when it’s cold again if the pattern repeats, and if so I will try removing the relay and see if 1) it cures the symptom or 2) the switch itself acts upon idle, which implies the timer unit of the heater is involved rather than the relay.
It was when I tried to understand if actual wiring is as expected from diagrams that I discovered the front screen heater has a timer unit. This what the manual says:
“……HEATED FRONT SCREEN
The heated front screen will operate when the
switch is operated with engine running. The timer
unit, see Relays-identification, will provide a preset
time cycle of 7 112 minutes + 20%.
Switching off the ignition, or further operation of
the heated front screen switch during the cycle will
switch off the screen and cancel, reset and switch
off the timer unit……”
Anybody knows what is the correct time? It obviously cannot be 7112, nor it can be 7 or 112. It could be 7/12 and a bad scan of the page on paper....
As far as I could inspect wiring is ok but... anybody knows why the oil pressure switch feeds into the front screen timer unit (as per diagram on manual)?
Sometimes the logic behind these things is really hard to pick up…..
Many thanks
Ciao
Adri