Pscan to adjust idle speed and reset learnt values

6 months 1 week ago #193311 by Jon-Mini
" Do all MPI Minis have an oil temperature sensor? "
well mine does , as seen in the log files , its a 1999 MPI mini so I'd guess they all do.

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6 months 1 week ago #193312 by pscan.uk
There are a number of "conditions" that the T4 sets before it will put the ECU into stepper motor calibration mode.
With some of these conditions it is clear what it is looking for but with others not so much.
For example it is clear that the coolant temperature must be at least 85 degrees C and then it forces the technician to wait for five minutes before checking the oil temperature.
However it isn't that clear what temperature it's looking for, so I am going to say 85 degrees C as well. Moreover I see no need to wait for five minutes if it's already there.
It also monitors engine revs and I think the throttle closed switch.

The first cut of this might be a little bit experimental but it should be out this week.

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6 months 1 week ago #193317 by pscan.uk
Can anyone tell me if there is an idle screw adjustment on other Rovers fitted with the MEMS2J, or is this unique to the MPI Mini?

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6 months 1 week ago #193318 by Roverlike

pscan.uk wrote: Can anyone tell me if there is an idle screw adjustment on other Rovers fitted with the MEMS2J, or is this unique to the MPI Mini?


As far as I know all throttle bodies for Rover 200/25/ZR have idle screw adjustment, either plastic or metal throttle bodies. Mems 2J is used in case of Vi and BRM so yes, they do have idle screw adjustment.
The following user(s) said Thank You: Jon-Mini

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6 months 6 days ago #193322 by pscan.uk
For those of you using Windows pscan042A is available and you can do stepper motor tuning on the MEMS2J.

I would appreciate some people to test it.

I have only tested it on an emulator at this time but it isn't the same as a real car.

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6 months 6 days ago #193323 by pscan.uk
Additionally, it would be good if some people who have a healthy car can test it.

If the only people who test it have warped throttle bodies or air leaks then we won't get very far.

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6 months 5 days ago - 6 months 5 days ago #193328 by pscan.uk
some screenshots of it in actions

Stage1. Waiting for the engine coolant to get to 85 deg C.


Stage2. The engine coolant now exceeds 85 deg C but the engine oil doesn't.


Stage3. After either 5 minutes, or the oil exceeds 85 deg C, pscan goes into calibration mode.


You would need to turn the idle stepper adjustment screw until a stepper reading of 26 is achieved. When you press "back" it should be saved.

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6 months 5 days ago #193329 by sworkscooper

Jon-Mini wrote: " Do all MPI Minis have an oil temperature sensor? "
well mine does , as seen in the log files , its a 1999 MPI mini so I'd guess they all do.

Hi Jon . Yes they all have an oil temperature sensor . Our Mini still has it but I replaced the dial for a pressure gauge some years ago now as I prefer to see pressure rather than temperature. The car now gives a fault code for open circuit for this but I just ignore it.
John

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6 months 5 days ago #193332 by Nickjowen
Hi Pscan,

I really appreciate you adding this function to the already brilliant diagnostic tool.

It has just fixed a “hanging idle issue” that I have had for the last 5 months. I had tried various new parts but to no avail.

I have just plugged in Pscan and it stated that my stepper position was at circa 26 steps when fully up to temperature. This made me think that the stepper motor was not the issue but I thought I would have a play with it as I could always set it back to where it was.

It is now set at 46 steps and idles at 920 ish and the revs no longer hang. It seems to be perfect with this set up.

Thanks very much.

Nick

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6 months 5 days ago #193333 by pscan.uk
Is it normal for them to work better at a different value to what Rover recommended?
or is it that the "calibration" does some magic as well?

When I started with this I was wondering if folks could achieve the same thing by putting stepper position on the screen in live data view and adjusting the screw to get 26, but as I got into it I realised that the T4 is doing more than that. It is interrogating the ECU for stepper value but there is also some "secret sauce" in there as well that I hadn't seen before.

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6 months 4 days ago #193336 by Nickjowen
I am not sure, but my engine is stage 3 with a 52mm Burlen throttle body, so maybe that makes a difference !!

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6 months 4 days ago #193337 by pscan.uk
yes it would. If the stepper motor is set to 26 then it can only close the throttle 26 step from where it is. When it gets to 0 there's no more and it can't control the idle.

If you have a bigger throttle then I guess it might need more than 26 to close it enough.

Go too far the other way and it would run out of steps to open the throttle if you load the engine (so all accessories switched on).

So I suppose on a hot idle with everything off you want a number towards the smallest end that you can get away with.

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