11 replies to this topic

[Mini'92]

Hi

have a 92 mini cooper spi just wondering how you go about resetting the ecu?? someone told me to turn the ignition on and press the accelerator 11 times but i just think he was pullling my leg.

or was he?

also i am thinking of a new head (stg2or3) and was wondering if the injection system would be affected by the better head?

thanks

[chairchild]

you reset the ECU every time you turn it on - it's why you cant reprogram the MEMS ECU

pressing the accelerator 10 times, with ignition at position 2 , recalibrates the TPS for the ECU, as they wear over time, and can give false information to the ECU - the usual "boost" in power that most people discover, is because their injection system is now actually working properly :wink:

[AlexM]

ill have to try that!

[AlexM]

Whats TPS?

[chairchild]

TPS = throttle position sensor; a variable resistor that's fitted to the butterfly so the ECU can know how far your foot is to the floor

[Sprocket]

you reset the ECU every time you turn it on - it's why you cant reprogram the MEMS ECU

pressing the accelerator 10 times, with ignition at position 2 , recalibrates the TPS for the ECU, as they wear over time, and can give false information to the ECU - the usual "boost" in power that most people discover, is because their injection system is now actually working properly :wink:

C**p

The reson you cannot reprogram the ECU is because the EPROMS (non volatile memory( needs no power to remember the information) that contain the program are embeded in the circuitry and nothing to do with resetting the ECU. They cannot be changed out like other ECUs for an EEPROM which can be rewritten, hence the term 'chipped'. The MEMS is the oddball ECU in that it is one of the only ones that you have to bin if you want to remap it.

Ok there are several 'myths' that no one person can give a reasonably factual answer to surrounding resetting the ECU. The first being resetting the ECU by depressing the accelerator 10 or 11 times with the ignition on. No one can substantiate this. Another method of resetting the ECU is to disconnect the battery for a period, this may work depending on the memory type. Again no one can substantiate this. One sure way of resetting the ECU is to use a diagnostic tool like the Crypton ACT. The true and sure way of ressetting the ECU is to use a Rover testbook which only Rover have and unfortunetly there aren't many dealers left that even know what they're doing.

As for the ECU resetting itself everytime the engine is switched on or off, this is untrue. Yes the memory may be volatile (needs power to remember the information( hence possible theory of resetting by removing power) but as long as there is power to the ECU the memory is fine. The ECU is adaptive and learns the tune of your engine as you drive it so as your air filter gets dirty and restricts air, the ECU will adapt the fueling and correct itself.

And as for calibrating the throttle, it only applies to the SPI. The throttle cam, NOT the pedal, is moved full throw with the ignition on and engine not running. This sets the stepper motor. The throttle cable can then be adjusted so that the prongs on the lost motion link are equaly spaced. This ensures the stepper is set at the right number of steps enabling correct control of idle air. Idle speed should NOT be set using the throttle cable.

TPS is short for throttle possition sensor. TPS is non adjustable. Its signal is proportional to throttle opening 0 volts fully closed 5v fully open. Idle is usualy around 0.4v with no vacuum leaks

[Sprocket]

also i am thinking of a new head (stg2or3) and was wondering if the injection system would be affected by the better head

Fitting a modified head should pose no problems and the ECU will adapt to the new characteristics.

[Dan]

Pumping the throttle is the Rover method for doing a quick reset of the fuel map back to factory. It's how you get rid of the learned programme so that when you fit a new air filter, it forgets about the choked up one and performs properly. It should be the last thing you do when you service an SPi, or especially when you tune it with anything like a performance air filter. It means that it will adapt to the new parts faster as it's working from the baseline and not from a learned map.

Exactly what the process is however is a mystery. Everyone tells you different things, but it definitely has to do with using the full throttle switch and not just flicking the throttle pot around. I thought that it had to be pressed five times in under ten seconds within twenty seconds of turning on the ignition (engine not running obviously) but you do hear many different stories about how it should be done.

[chairchild]

The thing about the memory resetting itself was pretty much a direct quite from Keith Calver by the way - I dont care much for how injection works, I hate it, and the instant my new engine's finished, I'm ripping out my bloody SPI setup

[Sprocket]

I have read every inch of the Rover Rave CD and nothing relates to using the throttle to reset the ECU. I did however find a document on this CD that states the ECU ' Adaption' can be reset to default values by using the 'Reset Adaptions' facility on the TestBook. If it was as easy as pressing the pedal several times I would have thought they would have said something. But then if it was that simple, there may be a chance that one of the general public may do this unintentionaly and upset the tune of the engine for a short period. I don't think Rover would let this happen as Unwanted suspected warranty claims would be very high. Not saying that its not the case but like I said, no one can substanciate it

[Sprocket]

The thing about the memory resetting itself was pretty much a direct quite from Keith Calver by the way - I dont care much for how injection works, I hate it, and the instant my new engine's finished, I'm ripping out my bloody SPI setup

This is extracted from another forum and the relavent bit is highlighted

Fraser (and others),
Thanks for your input on this subject but I have set this car aside with the problems unresolved waiting for a TestBook substitute to fully sort the problems out. The SnapOn unit is only a scanner and fairly useless in resetting adaptive values with this ECU and the experts (Keith Calver etc,) suggested are NONexperts on the subject of SPI and MPI Minis. There are no experts anywhere in the USA on the SPI or MPI unless you can give me a specific name or contact instead of a general Mini 'Expert'.
Paul, the answer is no I have not solved the problems yet. I would definetly check your cat and would also check the Rover recalls or updates, if you can get access, because I seem to recall that there was one on the topic of cam timing being off from the factory. Good luck!

Extracted from http://www.ilexa.co....pic,4898.0.html

[chairchild]

nice one :wink: