S60 vs Focus ST170 engine

[Alex DTA]

The reason it's cutting out is the cam tooth noise masking is on. When the cam moves, the cam tooth moves out of the window you have set.

The reason you have cam tooth noise masking on is you are seeing too many cam pulses.
The ST170 has 5 teeth, but your trace above shows 8.

I suspect the coil pack is feeding back in to the cam signal somehow, as the extra pulses are regular.

[haadee]

Thanks Alex for the reply, that makes good sense.
In my first post you can see when using the oscilloscope while cranking it does show only 5 pulses.
So I guess having 8 somehow has been my problem from the beginning?
8 pulses is probably the reason why it wouldn't run sequential on ST170 trigger mode (5 tooth) selected, that's why I had to use a filter.
That cam sensor filter is now my limiting factor.
I can set the high cutoff limit a few teeth higher without hitting the other pulse.
Am I thinking right, would 1 tooth higher, give me 10°crank so 5°cam range extra?

Another fix for this could be using shielded twisted pair cam wire?
I now have non shielded twisted pair.

[stevieturbo]

A full proper scope trace would be helpful.( ie, not DTA scope )

I think Alex is suggesting it is picking up the ignition pulse as the cam signal ? hence 8 "teeth"

But that might imply then it is not seeing any of the actual cam trigger teeth ?

[haadee]

A full proper scope trace would be helpful.( ie, not DTA scope )

I think Alex is suggesting it is picking up the ignition pulse as the cam signal ? hence 8 "teeth"

But that might imply then it is not seeing any of the actual cam trigger teeth ?

I could do that, but it is what the ECU sees and processes that dictates its actions.
Following that explanation, I don't know if an external real scope would help me.

[stevieturbo]

Following that explanation, I don't know if an external real scope would help me.

then you do not understand how a scope works, or the system

The DTA scope gives only vague information.

A real scope will give you a full picture of what is or is not being seen in terms of signals or interference

[Alex DTA]

I would definitely update the cam sensor wire to shielded.

As stevieturbo says, a proper oscilloscope will provide a lot more detail, but not everyone has access to one.

[stevieturbo]

Try unplugging the coils and get a DTA scope, and see if it sees any different "cam" teeth

[haadee]

I've put a scope on today, I was seeing interruptions and peaks sometimes that shouldn't be there.
That tells us we have interference, just as we knew from DTA scope.
Because the differences in cam pulses between cranking and running from the DTA scope.

I had to change my wiring now, so to be sure I put shielded wires to both crank and cam sensors.
Had it running again, looked on the DTA scope and saw the extra pulses that the ECU saw earlier were gone.
So I disabled the cam sensor filter I had on all the time.
This time the engine did fire up and run fine without the filter.

So this means the cam advance doesn't make the values go over the limits of the filter and stop it running.
I can run full VVT advance, all is good in the end.
When we made the loom, we thought if the Ford ECU can do without shielded wires so can the DTA ECU.
This was our mistake.

[stevieturbo]

So what was causing the extra pulses ?

[katana]

So what was causing the extra pulses ?

Likely, i'm guessing, interference. Signal critical wiring should obviously (recommended) be twisted pair and screened cable to minimise the possibility. Ford may have entirely different signal protocols to allow an un-shielded solution . . . . . . all to save a dozen pennies in wire costs across millions of multiple loom production costs?