mini spi idle issue (will idle untill throttle is moved then it will cut out)
Turbo Mini Forums

Hi everyone,

Had this problem for quite some time now and no ones really been able to shed any light on it for me, thought id ask again with a little more information.

so my mini will turn on and idle absolutely fine (cold and hot) as soon as the car is revved especially over 3k once the throttle is disengaged it will often not return to idle to cut out,

I had noticed the car had been running very lean, but then i checked the plugs again and it had been running really rich a few week later.. without anything being changed.

please note these are the things i have already tried:

1: standard ECU used
2: specialist components typhoon ECU used
3: car checked numerous times for an air leak (pipe from fuel trap to ecu, fuel trap to inlet, inlet to the valve on the other side)
4: air temperature sensor changed (green one on air filter)
5: stepper motor replaced

i also adjusted the lost motion link to get the prong in the middle of the two forks

any ideas please people??

if it stalls with the Specialist components ECU, either that if poorly tuned, or there is something fundamentally wrong with your engine

There's not enough information to give you any sort of real help. I want diagnostic information which includes the following

Idle RPM
Idle vacuum
idle advance
Idle stepper position
and whether the lambda sensor voltage is fluctuating.

other benefitial information is a four gas exhaust analysys, that includes

Idle CO
Idle HC
Idle O2
Idle CO2

Edited by Sprocket on 24th Mar, 2013.

thanks for the reply sprocket, tomorrow (or once the snow decides to leave) i will get all of these values for you

the lambda sensor is going hi to low, (maybe taking a little longer then a brand new one would though) could a faulty lambda sensor cause it to cut out like this?

what lambda sensor? also wideband or narrow band?

Here are some shots that i took of my ecu readout a while ago, i think the ones where the lamda was reading 0.97 constant was when the car was cold (is this normal) some reason one of them shows the lambda reading of 0 as well:S

i did also check the lambda sensor using a multi meter which fluctuated from about 200mV to about 500Mv was a while since i checked this


http://i1113.photobucket.com/albums/k513/j...hots/photo5.jpg

http://i1113.photobucket.com/albums/k513/j...hots/photo4.jpg

http://i1113.photobucket.com/albums/k513/j...hots/photo3.jpg

http://i1113.photobucket.com/albums/k513/j...hots/photo2.jpg

http://i1113.photobucket.com/albums/k513/j...hots/photo1.jpg

Too much going on here.

When I talk about diagnostic readings I'm talking about the standard ECU.

If you have stalling problems with the Specialist Components ECU, then I suggest you talk to Simon and John at Specialist Components. It's not that I can't help, it's just that it could become a conflict of interest.

If on the other hand you put the standard ECU back in, and provide the diagnostic information I ask for, I can start to point you in a direction that might help you solve your problem.

Please tell me though, does the Specialist Components ECU still use the stepper motor function? as that alone without proper tuning of the system can lead to stalling issues on overrun. It's not that it doesn't work, it just works in a different way to the standard ECU.

Any help with the Specialist components ECU will need comprehensive data logging while the event happens, a few pictures of the computer screen just wont cut it. This will be what Simon or John will also ask for. Logging is the key thing with any sort of programmable ECU. It allows you to sit down and analyze the mass of information presented at any one point in time.

I'll see if I can find anyone around my area with some diagnostics gear then! Thanks for the help!

okay so atm i dont know anyone with a diagnostics for the standard ECU and one on ebay is going for well over £200 which was the most i was prepared to pay :( (got outbid) will try some more to get some more information for you.

the SC ECU does use the stepper motor and i have actually been to SC and had simon get my car running with the ECU