Getting sequential to work

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
Rob Stevens
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Getting sequential to work

Post by Rob Stevens »

I have a Rover K Series that's been running great for years. So I decided to make the move to sequential injection, purely for my own curiosity and the hope of a couple of extra MPG's
Rover made a cam cover for later engines with a ready installed sensor (so I fitted one), this is a Hall effect, so I was unable to work out if this was 5v or 12v but it appears to work on 5v so may stick with that. I've wired all the injectors to an individual driver as they were paired to just 2 drivers.
This runs fine still in non - sequential mode but as soon as I turn sequential on it stalls.
On the oscilloscope it is clearly seeing the cam sensor but in diagnostics it doesn't show much, I did see once in 'cam1 Sig Tooth 16 but Angle 0.0'
Cam pulses received = 0
Cam sensor errors remains at 0

I've tried selecting the falling cam edge but it didn't change anything.

Any one have any ideas?
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stevieturbo
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Re: Getting sequential to work

Post by stevieturbo »

Is the crank/cam setup a known OEM configuration you can select within the software ? Or a makeup of different parts ?

Is cam signal mask maybe blocking something ?

Signal looks ok...although maybe a little odd the trigger isnt pulling to 0v, but if the scope sees it ok...it should be ok ? No idea what the internal thresholds are for a valid trigger to be detected, but there would be a low voltage threshold of some description.
Rob Stevens
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ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Getting sequential to work

Post by Rob Stevens »

Cam mask is off, I tried turning it on and adjusting the window but made no odds.
I thought the Hall low voltage of 0.6v was odd but I put that down to where I put the scope ground clip onto the head. I suspect that if I'd have grounded it to the sensor ground it would have been fine.
The crank is a known pattern and the cam I assume is also, there isn't a specific option, there is nothing special about it other than the cam trigger lump is 50% if the rotation but the ecu should just use the leading (or trailing) edge, you can see the 50% on/off signal in the trace.

I feel my pride dented a little as I thought I knew exactly what I should be doing!

Never done sequential before and I assumed it would just work, particularly with a hall sensor. I can't think why the DTA oscilloscope trace would look fine but the ecu running software does not appear to recognise the sensor.
stevieturbo
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Re: Getting sequential to work

Post by stevieturbo »

Sounds like it should just be a single tooth, as you say edge wont matter other than it's value being correct

But if the ecu isnt giving you a tooth position or saying there is no cam pulse received....but with a solid scope readout, I dunno really.

Defo one for Alex
Alex DTA
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Re: Getting sequential to work

Post by Alex DTA »

Should work fine as you have a good cam signal, but with the correct settings. Yours is roughly 180 degrees different to the one in the manual.

Upload a copy of the map.

Turn on sequential, then crank it over and see if it synchronises. I doubt it will.
Also take a crank scope with plug one in so we can calculate the correct cam angle. As you only have a single cam pulse, you shouldn't need any masking.
Rob Stevens
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ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Getting sequential to work

Post by Rob Stevens »

I've just done a bit more testing, but forgot to test for synchronisation whilst cranking, the cam sensor is seen always at tooth 13 or 14, not sure why it should change.
By changing the cam sensor position the engine does at least stutter to a halt, an improvement if you can call it that?!
I've done the cranking with one plug in and worked out the cam sensor is -130 deg, also a log of it stalling, you can see the the injector pulsewidth doubling and the ignition ramping up to stop it stalling.
All the friging around with the sensor position should only effect the timing of the pulse? I'm not bothered about that yet, it should still run fine even if the fuel timing is miles out??
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stevieturbo
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Re: Getting sequential to work

Post by stevieturbo »

I'd think yea, you should have a large window to play with for sensor position but the engine should still run pretty well.

Even for sparks, there's still a huge window where tooth position will still be telling the ecu cyl1 is next for it to work.

Although perhaps if it's going off/on sequential maybe that's why it isnt happy ? No idea what they use as a correction factor between batch and sequential, as the two modes will offer differing amounts of fuel I'd have though, especially at low duty cycles with one firing more than once per cycle.
Rob Stevens
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ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Getting sequential to work

Post by Rob Stevens »

I've tried again and it's like it can't see the cam sensor, I've tried it on the falling edge and at least then I get 14 come up in the cam angle in diagnostics. I then readjusted the cam position in sequential settings, but to no avail. It syncs fine in batch, but not in sequential.

Help!
Alex DTA
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Re: Getting sequential to work

Post by Alex DTA »

Hi Rob

I've got this on my radar, but it's been a bit manic the last few days. I'll get a look at it today or tomorrow.
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ignitionautosport
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Re: Getting sequential to work

Post by ignitionautosport »

I've always put in what I think is the angle, then set switch over point to 1200rpm or something and rev to that (with 10 degrees or whatever filling the map so I know what I'm going for), then watch with a timing light where the mark jumps to... as the engine dies... and adjust from there. Only takes a few goes to work out where it is then adjust.

So; there's an easier way? :roll: :mrgreen:
This was on a non-missing tooth engine though. A Toyota, using a Honda trigger mode from memory.
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