1980 UK 308GTS Marelli ACI200 Distributor set up query

I have a 1980 308GTS fitted with a single distributor ACI200 electronic Hall Effect system. The two VR sensors fitted inside the distributor body have damaged wiring, giving rise to misfiring problems.
Adrian over in Berlin has previously given us excellent info on all aspects of the system, I now have a question which may, or, may not, be relevant to setting up these two sensors.
As I understand it, the two sensors need to have an 'air gap' adjustment of between 0.25 - 0.4 mm to ensure the correct 'dwell' for the coils.
My question is, should the two sensors also be, phased, to each other, as you would an older system utilising a 'points' set up? If so how is this achieved, and, what settings should be used?
Any input would be most welcome.

 

Hi Peter,
I have never seen any mention by Adrian of this in my many hours of trying to understand this ignition system. But I think he is the only person who would answer this question with 100% certainty.
I have no knowledge of setting up a points system so I don't understand your question to be honest!
Regards
Andy

 

That's right about the air gap, you should use brass feeler gauges to set it and you need to remove a cover to make it easier.

From memory, there is no provision for adjustment for the phase, the sensors just fit in there and it is all supposed to be made with sufficient accuracy that you're within range when fitted. I remember approaching this wondering the same thing and ready to improvise something to measure it. In the end, I installed as-is, checked timing on both banks and found that there was no timing difference between banks, so the phase was ok. If it hadn't been, it would have been quite a pain to change.

Incidentally, what plug gaps are you using with the Marelli system?

 

As magnesium said, there is no provision for adjusting the phase. The sensor mounting plates have a single slotted hole for the air gap, the phase itself is fixed by the position of the screw holes in the body.

Best regards,
Adrian

 

Hi everyone, thanks for your replies. I am having problems getting my replies through, this is my third go so bear with me.
Thanks Adrian for confirming Magnesium's thoughts regarding setting up the 'phasing' of the VR sensors. I have been used to setting up V12's with twin Dizzy's and two points in each so you can see where I was coming from.
Andy, your photo's of the VR wiring in your Distributor mirrors what I found in mine. How on earth it worked, in this condition, is a mystery to me.
Re: magnesium's comment on plug gaps. I fitted NGK BPR8EIX plug's which were pre-set to 0.7mm (0.0275"). Last year I sorted out the Weber's and had a smooth idle with a good transition onto the main jets, no hesitation up or down the rev range so I assume the plug's were doing their job.
Regards,
Peter