Hi Folks,
I'm not giving up! I'm on a quest to understand my fuel injection system (2.0i 16v, Motronic 5.1.1). The next question is this. I was tinkering with my car last night (beautiful weather) and decided to check whether the idle speed stepper motor contibutes to anything by unplugging it with an idling warm engine. I unplugged it expecting hell to break loose...nothing happened. It behaved just as it did before. Can anyone explain this, do I need a new stepper motor?
I would be very happy if someone with the same engine could try the same thing to see what happens.
Niek.
btw I think I found my MAP sensor, they stuck it directly on the inlet manifold. (haven't fiddled with it yet)
Throttle housing and stepper motor
Moderator: RichardW
On a similar quest trying to sort out an intermittent cutout problem.
In reply to your question nothing should happen. the stepper motor will only do something if the load on the engine i.e. air conditioning cuts in, or lights get turned on (may be), changes or drops the idle speed, stepper motor will then bring it back to norm.
I think
Good luck
In reply to your question nothing should happen. the stepper motor will only do something if the load on the engine i.e. air conditioning cuts in, or lights get turned on (may be), changes or drops the idle speed, stepper motor will then bring it back to norm.
I think
Good luck
Hi Rickity,
Mine's suffering from intermittent cutouts as well. When it doesn't actually turn itself off the idle fluctuates before settling at about 600/650 rpm. When it does this the rpm tends to drop really fast as well (when changing gear for instance). Then again it sometimes works fine, no fluctuating idle (still a bit jerky), no cutouts and when unclutching(??) the idle sort of settles at 1000rpm first and then lowers to about 800.
Sound familiar??
Niek.
ps: should the stepper motor do anything when revving up and letting go of the accelerator?
Mine's suffering from intermittent cutouts as well. When it doesn't actually turn itself off the idle fluctuates before settling at about 600/650 rpm. When it does this the rpm tends to drop really fast as well (when changing gear for instance). Then again it sometimes works fine, no fluctuating idle (still a bit jerky), no cutouts and when unclutching(??) the idle sort of settles at 1000rpm first and then lowers to about 800.
Sound familiar??
Niek.
ps: should the stepper motor do anything when revving up and letting go of the accelerator?
Hey looks like theres more than one person on this hunt then? DarrenP seems to have the same problem with a 2.0-16V.
My 2.0 volcane has been doing exactly the same thing too. The ECU Fault light is on but it returns no error codes when i plug my gunsons tester into it. Cant be entirely sure that is working though.
My 2.0 volcane has been doing exactly the same thing too. The ECU Fault light is on but it returns no error codes when i plug my gunsons tester into it. Cant be entirely sure that is working though.
Hi Niek
your problem sounds sort of familiar, I have intermittent cut out for less than a second usually on acceleration after a period of gentle de-acceleration (cruise up to a junction then pull away, cutout, fill pants, carry on as normal). twice after a long high speed motorway run tickover stuck up at 2k eventually drops to normal after a couple of minutes stationary. I'm unable to repeat circumstances when cutout occurs. there is never any latch of a fault code. lamnda and map sensor replaced fault still apparaent.
So the blessed stepper motor
the idea is to control air that by passes the main throttle buterfly, basically to control idle speed. it appears that it can get stuck closed, open , midway and float about in the middle giving erratic idle or even be slow to respond. Stuck closed - cutout on idle, stuck open - high idle the other 2 conditons indeterminable.
In theory the stepper motor shouldn't be brought into play during revving up or letting go, but it is controlled by the ecu so anything can happen. it should be moved open when the engine is cold (equivalent to a choke)moving to closed as the engine warms. I guess your looking for away to test it and removing the temperature sensor might be one way, not at all sure though. There was something I read that suggested it may be oscillatting air flow controlled by the period closed to the period open, not a helpful scenario.
I actually got the courage to remove the stepper motor this weekend, gave it a clean and a push -pull (actually surprised I could push it in and pull it out was a bit tight to begin with - beware the spring if you try) and refitted it. took things a couple of miles to settle back down (idle speed all over the place ) but it seems ok now. haven't done enough miles to decide about the intermittent cutout yet, but it feels livelier.
So there you have the whole story, if it helps in any way great if no sorry for the long post.
rickity
your problem sounds sort of familiar, I have intermittent cut out for less than a second usually on acceleration after a period of gentle de-acceleration (cruise up to a junction then pull away, cutout, fill pants, carry on as normal). twice after a long high speed motorway run tickover stuck up at 2k eventually drops to normal after a couple of minutes stationary. I'm unable to repeat circumstances when cutout occurs. there is never any latch of a fault code. lamnda and map sensor replaced fault still apparaent.
So the blessed stepper motor
the idea is to control air that by passes the main throttle buterfly, basically to control idle speed. it appears that it can get stuck closed, open , midway and float about in the middle giving erratic idle or even be slow to respond. Stuck closed - cutout on idle, stuck open - high idle the other 2 conditons indeterminable.
In theory the stepper motor shouldn't be brought into play during revving up or letting go, but it is controlled by the ecu so anything can happen. it should be moved open when the engine is cold (equivalent to a choke)moving to closed as the engine warms. I guess your looking for away to test it and removing the temperature sensor might be one way, not at all sure though. There was something I read that suggested it may be oscillatting air flow controlled by the period closed to the period open, not a helpful scenario.
I actually got the courage to remove the stepper motor this weekend, gave it a clean and a push -pull (actually surprised I could push it in and pull it out was a bit tight to begin with - beware the spring if you try) and refitted it. took things a couple of miles to settle back down (idle speed all over the place ) but it seems ok now. haven't done enough miles to decide about the intermittent cutout yet, but it feels livelier.
So there you have the whole story, if it helps in any way great if no sorry for the long post.
rickity
Hi Guys,
Thanks for the posts. Good to know I'm not the only one out here with problems of this kind. Thanks for the explanation of the stepper motor. I've decided to take the whole throttle housing out (sometime in the next week orso) and give the thing a good clean. I'll clean all the sensors on it as well. (stepper, air temp and throttle position sensor (TPS)) I'll let you folks know how that turns out.
One last question mark, how does the motormanagement regulate the way the RPMs drop when revving high and then letting go? It doesn't drop like a brick because that would be too uncomfortable yet it sometimes drops alot faster and lower than at other times (this is why I thought the stepper motor came into play because it's the only thing (is it??) that alows the ECU to control the rpm...)
Niek.
Thanks for the posts. Good to know I'm not the only one out here with problems of this kind. Thanks for the explanation of the stepper motor. I've decided to take the whole throttle housing out (sometime in the next week orso) and give the thing a good clean. I'll clean all the sensors on it as well. (stepper, air temp and throttle position sensor (TPS)) I'll let you folks know how that turns out.
One last question mark, how does the motormanagement regulate the way the RPMs drop when revving high and then letting go? It doesn't drop like a brick because that would be too uncomfortable yet it sometimes drops alot faster and lower than at other times (this is why I thought the stepper motor came into play because it's the only thing (is it??) that alows the ECU to control the rpm...)
Niek.
Niek
And there lies the problem, the ecu controls the rpm by sensing all the inputs from the throttle pot, temp, rpm, air temp, map, lamda, and adjusting injector, timing, and spark and yes the blessed stepper motor to acheive what is been programed to do. unfortunatly one rogue item with a dirty contact, lump of dirt, or dodgey sensor will provide a varity of symptoms that don't look as if they're connected.
If only the real information was available and sufficient test gear we might be able to stop guessing.
If any one has a source of info about ecu's please tell us about it.
rickity
And there lies the problem, the ecu controls the rpm by sensing all the inputs from the throttle pot, temp, rpm, air temp, map, lamda, and adjusting injector, timing, and spark and yes the blessed stepper motor to acheive what is been programed to do. unfortunatly one rogue item with a dirty contact, lump of dirt, or dodgey sensor will provide a varity of symptoms that don't look as if they're connected.
If only the real information was available and sufficient test gear we might be able to stop guessing.
If any one has a source of info about ecu's please tell us about it.
rickity
Hiya
this problem does seem like the one I had, but now seems to be fixed when i replaced the map sensor (fitted directly to the inlet manifold just after buterfly)I found that the car would exhibit the same symptoms when I fiddled with the map sensor plug.
I replaced the plug first which made it better but then I had to replace the sensor aswell, there seemed to be a problem with the conncetion but i could not fix it without a new sensor maybe the pins were coming away from the sensor internally.
My Xsara vts does seem to idle a little roughly when its hot any ideas what that could be , I would clean the stepper motor but I dont know where it is on the throttle housing as their are a few bits and pieces on there.
Darren......
this problem does seem like the one I had, but now seems to be fixed when i replaced the map sensor (fitted directly to the inlet manifold just after buterfly)I found that the car would exhibit the same symptoms when I fiddled with the map sensor plug.
I replaced the plug first which made it better but then I had to replace the sensor aswell, there seemed to be a problem with the conncetion but i could not fix it without a new sensor maybe the pins were coming away from the sensor internally.
My Xsara vts does seem to idle a little roughly when its hot any ideas what that could be , I would clean the stepper motor but I dont know where it is on the throttle housing as their are a few bits and pieces on there.
Darren......
Darren
this ain't easy and a photo may be the answer.
The stepper motor can be found about an inch to the right of the throttle cable wheel ( towards the air filter)and back towards the engine but still on the air intake block. It looks black, its round about the diameter of a 2p coin, about 1.25 inches long, its held in by 2 screws diametericaly oppisit. electical connector has 4 wires comeing from it (4??)
Hope that helps wel thats how I think it is anyway.
Rickity
this ain't easy and a photo may be the answer.
The stepper motor can be found about an inch to the right of the throttle cable wheel ( towards the air filter)and back towards the engine but still on the air intake block. It looks black, its round about the diameter of a 2p coin, about 1.25 inches long, its held in by 2 screws diametericaly oppisit. electical connector has 4 wires comeing from it (4??)
Hope that helps wel thats how I think it is anyway.
Rickity
Yup, 4 wires coming from it.
Be careful though when you clean it. I was told that all you could clean is the 'dome' that sits at the end of the stepper motor. Don't force it in and out (although I read something somewhere of someone (that clears things up right <img src=icon_smile_big.gif border=0 align=middle>) who did) because you might damage the gears.
Maybe it's a better idea to take the whole throttle housing off ans cleaning the lot.
Have fun,
Niek
Be careful though when you clean it. I was told that all you could clean is the 'dome' that sits at the end of the stepper motor. Don't force it in and out (although I read something somewhere of someone (that clears things up right <img src=icon_smile_big.gif border=0 align=middle>) who did) because you might damage the gears.
Maybe it's a better idea to take the whole throttle housing off ans cleaning the lot.
Have fun,
Niek
Hey,
Had time for this as well. Took the entire throttle housing off the inlet manifold. It was completely covered (on the inside) with black gum. (car has done 180.000 km and I doubt that the housing had ever been off) I took everything off the housing (tps, stepper motor, heater and a plastic back-plate) and cleaned everything. One thing I noticed before cleaning is that the throttle butterfly couldn't really close properly anymore because of the gum. I paid special attention to the by-pass the stepper motor sits in.
Anyway the cars is definetly smoother now and hasn't shown the erratic idling/stalling business anymore. If it does resurface (wouldn't be surprised) I'll post again...
Niek.
Had time for this as well. Took the entire throttle housing off the inlet manifold. It was completely covered (on the inside) with black gum. (car has done 180.000 km and I doubt that the housing had ever been off) I took everything off the housing (tps, stepper motor, heater and a plastic back-plate) and cleaned everything. One thing I noticed before cleaning is that the throttle butterfly couldn't really close properly anymore because of the gum. I paid special attention to the by-pass the stepper motor sits in.
Anyway the cars is definetly smoother now and hasn't shown the erratic idling/stalling business anymore. If it does resurface (wouldn't be surprised) I'll post again...
Niek.
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stuart graham
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I also have an intermittent cutting out 1998 1.8 16v Xsara, and have been round the whole system so far and have come to the conclusion that it could be the coils.
the car can run for weeks with no faults the out of the blue will judder as your driving along as if its 'missed' some times the engine cuts out altogether normally it will kick back in after dipping the clutch, also when idling the revs drop to around 600 - 700 rpm and the engine is very lumpy, when this has happened I have been over all the connections but no joy any one any thoughts, great car otherwise.
I read in one of the replies that the gunsons ecu tester works on the xsara diagnostic socket anyone got a part no or model number for this device and how much are they.
many thanks to anyone who takes time to scratch the grey matter and respond[:o)]
the car can run for weeks with no faults the out of the blue will judder as your driving along as if its 'missed' some times the engine cuts out altogether normally it will kick back in after dipping the clutch, also when idling the revs drop to around 600 - 700 rpm and the engine is very lumpy, when this has happened I have been over all the connections but no joy any one any thoughts, great car otherwise.
I read in one of the replies that the gunsons ecu tester works on the xsara diagnostic socket anyone got a part no or model number for this device and how much are they.
many thanks to anyone who takes time to scratch the grey matter and respond[:o)]
Loads of useful information on this site - possibly worth a look under Peugeot as well
http://www.bba-reman.com/index.htm
Gunsons code readers are about £20 and are sold by Halfords - may be something on their web site about them (possibly Gunsons as well but never looked)
http://www.bba-reman.com/index.htm
Gunsons code readers are about £20 and are sold by Halfords - may be something on their web site about them (possibly Gunsons as well but never looked)