Quick question (hopefully)
Car - 1997 1275 mpi cooper
Issue - Idle revs sit way too high (around 2,500 rpm) when the car is warming up. Idle revs seem fine when the engine is cold and when the engine gets to full working temp (after about 25 mins running). When going through the gears the revs race up when i depress the clutch then decrease as the clutch engages again
have checked there's no interference between the clutch mechanism and throttle cable and all seems fine. I've noticed if I take the car on a longer journey the issue goes away after about 25 mins running
I've searched through some topics and found the the stepper motor can sometimes cause this if it sticks.
Would anybody be able to advise how I can test if this is the stepper motor (hopefully without buying a new one to rule it out)
or alternatively other issues that it may be ?
Many thanks
Stepper Motor Issue ?
Started by
silver_toes
, Nov 27 2012 02:09 PM
9 replies to this topic
#1
silver_toes
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Posted 27 November 2012 - 02:09 PM
#2
MiniAida
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Posted 27 November 2012 - 02:27 PM
Hi Silver toes,
Have you tried resetting the stepper motor? The way to do it for the SPi is;
Turn ignition on 2 clicks - depress accelerator about 6 times (it's about 10 for my land rover which uses MEMS too) - listen for whirring click from around the throttle body - turn off then start engine as usual.
There is a way of seeing if the unit is working in this Haynes manual on
www.gaima.co.uk/peter/RoverMEMS.pdf
Good luck!
MA
Have you tried resetting the stepper motor? The way to do it for the SPi is;
Turn ignition on 2 clicks - depress accelerator about 6 times (it's about 10 for my land rover which uses MEMS too) - listen for whirring click from around the throttle body - turn off then start engine as usual.
There is a way of seeing if the unit is working in this Haynes manual on
www.gaima.co.uk/peter/RoverMEMS.pdf
Good luck!
MA
#3
Nu2mini
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Posted 27 November 2012 - 03:14 PM
Why is taking 25 minutes for the car to get to temperature. It should be there in about 5 minutes even at this time of year. I'd first check the thermostat is working properly and the cooling system is flushed.
To check the stepper motor you need to plug the car into a diagnostics reader. This can either be done by s friendly garage or post a plea for assistance for someone near you in the injection section
To check the stepper motor you need to plug the car into a diagnostics reader. This can either be done by s friendly garage or post a plea for assistance for someone near you in the injection section
#4
silver_toes
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Posted 27 November 2012 - 08:49 PM
Hi all,
thankyou for the responses. The car has only developed the issue over the last few weeks. I assumed it was something to do with the colder weather.
I'll check the temp sensor and associated connections at the weekend. There's never any time to do anything on the mini after work these days with the continuous rain and long dark nights
Cheers
Liz
thankyou for the responses. The car has only developed the issue over the last few weeks. I assumed it was something to do with the colder weather.
I'll check the temp sensor and associated connections at the weekend. There's never any time to do anything on the mini after work these days with the continuous rain and long dark nights
Cheers
Liz
#5
silver_toes
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Posted 16 December 2012 - 04:39 PM
Argghhhh, thought i had this licked. Cleaning the iacv seemed to fix the problem for a few days but now it's back. I have cleaned all throttle body connectors and had the iacv out and cleaned it. I did notice that the iacv had a couple of grooves on the metal bit at the end. Is this a problem ?
Cheers
Liz
Cheers
Liz
#6
silver_toes
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Posted 12 January 2013 - 12:02 PM
Hi All,
Re high idle issue.
This is my last cry for help before the car goes in to the garage.
I never really got to the bottom of this issue. I thought i'd fixed it when I took the idle air control valve out and cleaned it. This seemed to resolve the problem temporarily. The car has reverted back to it's high idle of between 2000 and 2500 rpm. I left it running for five minutes to get up to temp this morning. After it was up to temp i blipped the throttle and this brought the idle back to 1500 (which is still too high)
I've swapped the iacv out with one i know works and this hasn't helped. Cleaned the iacv, had the water temp sensor and inlet air temp sensor out and cleaned all 3. Checked the throttle cable isn't sticking and the butterfly mechanism in the throttle body closes completey. Can't see any warping or cracking on the throttle body - although it is an original plastic type.
I've sprayed carb cleaner all around the hoses on the throttle body this morning to see if I can find an air leak but to no avail.
If anyone can help with any ideas it would be very much appreciated. I've put a link to a video of the problem below.
Not sure if this is related but the coolant seemed to be boiling away in the expansion tank before i took the video. This stopped when the car reached operating temp and the fan came on a short while later. The car's not smoking (white or black)
I've had the car plugged in to a diagnostic thingy at a garage. The diagnostics said that the ambient air temp sensor was reading -270 odd degrees. Could it be that my inlet air temp sensor is knackered, if so is there a way of testing it ?
Here's an video of the symptoms.
Many thanks for taking the time to look.
Cheers
Liz
https://www.dropbox....12-11-19-54.mp4
Re high idle issue.
This is my last cry for help before the car goes in to the garage.
I never really got to the bottom of this issue. I thought i'd fixed it when I took the idle air control valve out and cleaned it. This seemed to resolve the problem temporarily. The car has reverted back to it's high idle of between 2000 and 2500 rpm. I left it running for five minutes to get up to temp this morning. After it was up to temp i blipped the throttle and this brought the idle back to 1500 (which is still too high)
I've swapped the iacv out with one i know works and this hasn't helped. Cleaned the iacv, had the water temp sensor and inlet air temp sensor out and cleaned all 3. Checked the throttle cable isn't sticking and the butterfly mechanism in the throttle body closes completey. Can't see any warping or cracking on the throttle body - although it is an original plastic type.
I've sprayed carb cleaner all around the hoses on the throttle body this morning to see if I can find an air leak but to no avail.
If anyone can help with any ideas it would be very much appreciated. I've put a link to a video of the problem below.
Not sure if this is related but the coolant seemed to be boiling away in the expansion tank before i took the video. This stopped when the car reached operating temp and the fan came on a short while later. The car's not smoking (white or black)
I've had the car plugged in to a diagnostic thingy at a garage. The diagnostics said that the ambient air temp sensor was reading -270 odd degrees. Could it be that my inlet air temp sensor is knackered, if so is there a way of testing it ?
Here's an video of the symptoms.
Many thanks for taking the time to look.
Cheers
Liz
https://www.dropbox....12-11-19-54.mp4
Edited by silver_toes, 12 January 2013 - 12:02 PM.
#7
Carlos W
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Mine is purple, but I have been told that's normal
- Location: Sittingbourne, Kent
Posted 12 January 2013 - 12:32 PM
The diagnostics said that the ambient air temp sensor was reading -270 odd degrees.
This could be the issue, it may be worth replacing!
Hi Silver toes,
Have you tried resetting the stepper motor? The way to do it for the SPi is;
Turn ignition on 2 clicks - depress accelerator about 6 times (it's about 10 for my land rover which uses MEMS too) - listen for whirring click from around the throttle body - turn off then start engine as usual.
There is a way of seeing if the unit is working in this Haynes manual on
www.gaima.co.uk/peter/RoverMEMS.pdf
Good luck!
MA
Did you try this?
Is the water in the expansion tank boiling or are you just seeing it swirling whilst the thermostat is closed and it's coming through the bypass?
#8
silver_toes
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Posted 12 January 2013 - 12:38 PM
Hi Carlos, thanks for the reply.
The coolant in the expansion tank is sort of swirling rather than boiling I guess.
Yes, I've tried re-setting the stepper motor initially and after each time I've had it out.
I may see if I can get hold of a new inlet air temp sensor and try that. If that sensor was knackered might that explain the idle behaviour ?
Many thanks again
Liz
The coolant in the expansion tank is sort of swirling rather than boiling I guess.
Yes, I've tried re-setting the stepper motor initially and after each time I've had it out.
I may see if I can get hold of a new inlet air temp sensor and try that. If that sensor was knackered might that explain the idle behaviour ?
Many thanks again
Liz
#9
Carlos W
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Mine is purple, but I have been told that's normal
- Location: Sittingbourne, Kent
Posted 12 January 2013 - 12:40 PM
The cars ecu will change the fuelling of the car depending upon air temperature, so it is likely to change how the car runs if this isn't working correctly as it will be sending the wrong information
#10
silver_toes
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Posted 20 January 2013 - 12:36 PM
Have finally managed to fix this issue so I thought i'd update the topic in case it is of any use to anyone else.
I noticed that I could control this problem by leaving the car to warm up in the morning, then turning it off and back on again a few seconds later. The idle would go from 2000 initally then when i restarted the warmed up engine sit nicely at around 1000 revs.
I changed the inlet air temp sensor this morning
(this bit http://www.somerford...roducts_id=5294 )
and it seems to have fixed the problem. Car now idles nicely at 1000 revs even when warming up from cold.
Many thanks for all the help on this thread. I can get back to the original list of things which needed fixing on the car before this popped up
I noticed that I could control this problem by leaving the car to warm up in the morning, then turning it off and back on again a few seconds later. The idle would go from 2000 initally then when i restarted the warmed up engine sit nicely at around 1000 revs.
I changed the inlet air temp sensor this morning
(this bit http://www.somerford...roducts_id=5294 )
and it seems to have fixed the problem. Car now idles nicely at 1000 revs even when warming up from cold.
Many thanks for all the help on this thread. I can get back to the original list of things which needed fixing on the car before this popped up
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