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different idle problem after new stepper motor
Posted: Sat May 06, 2006 2:53 pm
by mivecboy
I ve replaced my stepper motor few weeks ago due to idle die out when cold and when aircon is switched on.
This has fixed the problem but I'm experiencing another 2 issues:
1) idle will bounce up and down between 900 - 1600rpm when doing half to full steering turn whether stationary or moving.
2) When cold start, idle is very high at 2500 - 3000rpm for few minutes, then it would bounce up and down between 1500 - 2100rpm for another few minutes before it settles down to normal idle rpm. I remember back when my old stepper motor was working properly, cold start did not go above 2000rpm. So reving at 3000rpm when cold is not doing the engine any good. What does your FTO revs when cold?
I've resetted my ecu twice with no cure to the above problems
please advise?
Posted: Sat May 06, 2006 3:44 pm
by rnbboi
can i just ask where did u get your car from? if its from a dealer can u please post the name and address of it... cos it seems that ever since u got your car, its been playing up on u
anywayz, when i start my car in the mornings, it idles just above 1k, and eventually settles down to under 1k.
Posted: Sat May 06, 2006 4:06 pm
by mivecboy
bought it private.
Posted: Sat May 06, 2006 5:18 pm
by Bennoz
Sounds like that stepper is a bit dodgy... did you buy it new? It also might be the TPS unit (throttle position sensor.) Its the black plastic housing bolted to the front side of the throttle body. I'd suggest removing it & carefully cleaning it & putting it back on. Alternatively you can actually adjust the TPS using this guide:
http://www.ftooc.org/phpbb/viewtopic.php?t=45401
Posted: Tue May 09, 2006 5:40 pm
by know1here
My car idled around 2-3000 after I changed my stepper, but it came back down after a week or two, and now running at normal rpms.....i think the ECU just had to get used to it again, and maybe by resetting your ECU again and again, it hasn't had time to settle itself back down???
Re: different idle problem after new stepper motor
Posted: Tue May 09, 2006 6:03 pm
by SG
mivecboy wrote:I ve replaced my stepper motor few weeks ago due to idle die out when cold and when aircon is switched on.
This has fixed the problem but I'm experiencing another 2 issues:
i've replaced my stepper motor with a new one awhile ago and have been getting that recently.. its a prob with the air con unit, or something. theres no probs with idle at all when the air con is turned off when i start the car or turn it off just after starting it. sounds like the car is miss-firing though if the aircon is on. (running on 2 or so cylinders)
i get the idle bounce aswell when turning but i'm told thats normal as the motor wants to keep the revs up, to stop leaning out on corners or something, but i'm not sure about that.. its not a direct injection motor but i dont think it'll stop receiving fuel if you turn suddenly
have you tried resetting / training the ecu with the aircon off?
Posted: Wed May 10, 2006 10:22 am
by mivecboy
Yes, I have resetted the ecu twice and with aircon off. Still the same.
The idle bounce up and down when turning just doesn't make sense to me.
Posted: Wed May 10, 2006 9:36 pm
by mivecboy
I ve also drove more than 500km after resetting ecu.
Same problem.
Could sensors need adjustments?
Posted: Wed May 10, 2006 11:06 pm
by Bennoz
TPS! See above
Posted: Wed May 10, 2006 11:24 pm
by bigpitty1
The ECU has to relearn how to idle again, it will bounce for a while and in a couple of days it should be fine, it took mine to relearn about 2 weeks.
Posted: Thu May 11, 2006 12:27 am
by khunjeng
Bennoz wrote:TPS! See above
i'm with ben...check this out first. did u have the TB off??
Posted: Thu May 11, 2006 1:42 am
by SchumieFan
bigpitty1 wrote:The ECU has to relearn how to idle again, it will bounce for a while and in a couple of days it should be fine, it took mine to relearn about 2 weeks.
Are you on crack?
Posted: Thu May 11, 2006 10:10 pm
by bigpitty1
that what happened with mine, in 2 weeks it was fine again, it probably took so long coz I only drive my FTO on the weekend.
Posted: Thu May 11, 2006 11:29 pm
by mivecboy
I drove mine 40kms everyday and clocked 500km so far. If ecu doesn't learn by now then it must be stupid.
Posted: Thu May 11, 2006 11:38 pm
by khunjeng
bigpitty1 wrote:that what happened with mine, in 2 weeks it was fine again, it probably took so long coz I only drive my FTO on the weekend.
only needs 100kms accoring to the sevice manual. I have done it heaps and seems to work itself out after 50-70kms...
so if it hasn't fixed up bu 100 u have another issue.
dod u check the TB and the TPS??
Posted: Fri May 12, 2006 10:12 am
by mivecboy
I'm not confident enough to work on these sensor. But would like to get my hands dirty if I have someone experienced around. I live in Doncaster btw and can travel if someone here knows how.
Posted: Mon May 15, 2006 10:36 pm
by Storm
When you switch on your air con the revs rise because you are running an extra pump so the engine compensates for this by giving a little extra power.
Now here comes the technical bit so pay attention.
When you turn the steering wheel the power steering pump kicks in so the engine is running an extra pump and compenstes by giving a little rise in revs to bring some extra power.
Simple really

Posted: Tue May 16, 2006 1:49 pm
by mivecboy
Thanks Storm.
But this bouncing rev is very annoying at its bouncing very high to 2000 rpm sometimes when turning! this is kind of dangerous when im doing a slow corner. Same goes for my air-con when switched on. My old stepper motor never rev this high when idle, so do I hv a dodgy stepper (I was told its a new replacement) or if there is adjustment I can make to fix this?
Posted: Tue May 16, 2006 10:18 pm
by Storm
mivecboy wrote:Thanks Storm.
But this bouncing rev is very annoying at its bouncing very high to 2000 rpm sometimes when turning! this is kind of dangerous when im doing a slow corner. Same goes for my air-con when switched on. My old stepper motor never rev this high when idle, so do I hv a dodgy stepper (I was told its a new replacement) or if there is adjustment I can make to fix this?
I'm not sure about the bouncing, 2k does seem a bit high. The inly experience I have had with bouncing revs was it dropping at 30mph. That was the TPS which needed reseting and theres a write up on the UK FTOOC about checking it. You will get it by clicking
here
HTH
Storm
Posted: Tue May 16, 2006 11:37 pm
by bigpitty1
It could be a vacume leak, when your car is at idle, pump the brakes a few times, do the revs change, if it does your brake booster might be leaking
Also check all your vacume lines, check to see if the new stepper motor is on properly, it maybe loose or something.