Over revving
- Thread starter Steve. H
- Start date
. Hope you can get your Zed working properly 
Steve. H
Regular Member
Robert, I didn't realise that the second cable was actually the cruise control. That's why I asked about it. It doesn't work anyway!
Today I disconnected the cruise cable & unplugged it.... no difference. Again if I turn off ASC it works ok.
I've checked all the lights are working, the two sensors on the throttle have also been replaced. All fuses ok.
Today I disconnected the cruise cable & unplugged it.... no difference. Again if I turn off ASC it works ok.
I've checked all the lights are working, the two sensors on the throttle have also been replaced. All fuses ok.
Welcome to the forum from Egg Harbor Township, New Jersey. I was reading about your problem. I haven't worked on my Z much with respect to the engine so I can't give much advise with respect to this car. There are some things that peak my interest though. Usually with 2 cables going to the throttle body, one is the throttle cable and the other is the throttle cable coming fron the diaphram of the cruise control. You say that it doesn't happen under 25 mph. Generally in many cars, that is the speed at which the cruise control begins to work or if you are driving with the cruise control operating, once you go under 25 mph, the cruise control automatically cuts out. It might be possible that there is a problem with your cruise control that turns it on OR keeps it from shutting off so that once you reach 25 mph it activates by itself and begins to accelerate the vechile by itself. If the switch were defective and telling the car to accelerate once the 25 mph speed was reached, it might have the effect you are describing. An interesting thing you can do is when the car is acting this way, slow it down with the brakes to under 25 mph to see if it stops accelerating by itself. If this happens, I would assume that the part of the cruise control switch that controls acceleration is faulty or perhaps if not the switch, then the module. It might be interesting to see at what speed your car stops self accelerating. Naturally, this would have to be done on an open highway where you wouldn't have to worry about other traffic. If it continuously accelerats, then the accelerating part of the switch is bad. Some cars have an on/off switch for cruise control but I haven't found one on my Z so I think it's always hot. There might be another problem. If your cruise control switch works properly, when you give the signle for it to increase the car's speed, it tells the cruise control module to increase the vacuum in the diaphram of the cruise control which pulls harder on the cable attached to it, the other end of which goes to your throttle body thus increasing your speed. If your cruise control module keeps increasing your speed REGARDLESS of what you're doing or not doing with your switch in the car, you're just going to keep accelerating. This cruise control module may not be able to shut down when reaching ANY speed regardless of your imput intentions inside the car with your switch unless you hit the 25 mph cut off. Then the module would be bad. Please keep me informed as to what you finally find the problem to be.....................Frankie
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Steve. H
Regular Member
Frankie,
I can't see how this could be, as I said previously, I have unplugged it & removed the cable. The problem still occurs. The only thing that make it go normally is switching the ASC off.
I can't see how this could be, as I said previously, I have unplugged it & removed the cable. The problem still occurs. The only thing that make it go normally is switching the ASC off.
This could be an asc fault it is designed to brake/accelerate wheels to compensate for differences it may well be worth getting the system code read to see if it shows anything up the system self checks but if its getting spurious readings it could act strangely.
It goes away if the ASC is turned off. For now I think we have to assume that's where the issue is.
If someone can explain about the apparently 2 different types of ASC and where I find the equipment for the version that isn't embedded near the MAF I can hopefully identify the right spare and get Steve sorted.
I've read up on ASC but what I can find refers to that version with the secondary throttle near the MAF. My brother's 1.9 doesn't have that, my 1.9 breaker didn't have it and Steve's car doesn't have it.
I need to work out which version Steve's car should have as it's possible it's the one next to the MAF and it's been deleted for the air filter mod. If it's the other version I don't know where to find it or even what it looks like to dig a spare out!
It's a good thought on the cruise control but maybe best to park that up until we investigate the more obvious ASC link.
Don't forget Steve that it's just possible it might be literally what the error message says and it's the console switch - but I struggle to believe that.
If someone can explain about the apparently 2 different types of ASC and where I find the equipment for the version that isn't embedded near the MAF I can hopefully identify the right spare and get Steve sorted.
I've read up on ASC but what I can find refers to that version with the secondary throttle near the MAF. My brother's 1.9 doesn't have that, my 1.9 breaker didn't have it and Steve's car doesn't have it.
I need to work out which version Steve's car should have as it's possible it's the one next to the MAF and it's been deleted for the air filter mod. If it's the other version I don't know where to find it or even what it looks like to dig a spare out!
It's a good thought on the cruise control but maybe best to park that up until we investigate the more obvious ASC link.
Don't forget Steve that it's just possible it might be literally what the error message says and it's the console switch - but I struggle to believe that.
Steve. H
Regular Member
I'll get another switch and try it Robert but that will take a few days.
- Joined
- Dec 8, 2011
- Points
- 145
@Steve. H Please confirm that there is only one cable attached to your throttle body.
Looking at this, it looks like you have the earlier model of ASC (without the auxiliary throttle). ASC starts of p.153. If you had the newer type, you would have an ADS actuator (shown as M93 on image 3 of p.342)
If you have an ADS actuator fitted, please let us know. This will help confirm the type of ASC fitted.
I wouldn't bother with buying a new switch until you have tested it and the wiring to it. A switch is just a switch.
Looking at this, it looks like you have the earlier model of ASC (without the auxiliary throttle). ASC starts of p.153. If you had the newer type, you would have an ADS actuator (shown as M93 on image 3 of p.342)
If you have an ADS actuator fitted, please let us know. This will help confirm the type of ASC fitted.
I wouldn't bother with buying a new switch until you have tested it and the wiring to it. A switch is just a switch.
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This was beginning to send me a bit loopy @Pingu so I'm glad you've confirmed there are 2 different types.
So the early type has no secondary/auxillary throttle at all? That will explain why I couldn't find it on Steve's car or my brother's! How does the ASC control the throttle?
And the later type has the actuator ('M93') plus the secondary throttle - which I believe sits behind the MAF? Which I believe is what we are looking at in this picture?
I'll let Steve confirm for sure but I've seen his car and I don't think it's the type in the picture. Either that or it's been deleted.
- Joined
- Dec 8, 2011
- Points
- 145
The ADS actuator (M93) is not the part arrowed, but I'm pretty sure it is in the image. I think it is the part in the top right corner in the loop of the throttle cables. (see image 3 on p.342 of the wiring diagram [http://www.porterbility.co.uk/Files/PDF/e36z3_98_AG.pdf])This was beginning to send me a bit loopy @Pingu so I'm glad you've confirmed there are 2 different types.
So the early type has no secondary/auxillary throttle at all? That will explain why I couldn't find it on Steve's car or my brother's! How does the ASC control the throttle?
And the later type has the actuator ('M93') plus the secondary throttle - which I believe sits behind the MAF? Which I believe is what we are looking at in this picture?
I'll let Steve confirm for sure but I've seen his car and I don't think it's the type in the picture. Either that or it's been deleted.
If I'm right and he doesn't have M93, his ASC works by applying the brakes, rather than by cutting power.
Steve. H
Regular Member
I don't have this kind of set up. The date of registration is 24.02.97. 1895cc
I think I have the early type set up that Robert talks about & as can be seen in my previous pictures.
I don't have the set up as pingu speaks about.
I think I have the early type set up that Robert talks about & as can be seen in my previous pictures.
I don't have the set up as pingu speaks about.
This is of great interest to me as I am collecting parts to retrofit CCto my 97 1.9 build date Jan 1 97 I believe. I don't have ASC on my car and took my parts list from the BMW site. It will be interesting to see the result and solution of this problem. Is it possible that the clutch switch is faulty as it should cut out the CC when the brake is applied?
from me 
Steve. H
Regular Member
Quick update,
I've change the ASC switch, it makes no difference.
To clarify with ASC turned on the car increases in speed when driving.
The cc does work, I can increase and decrease speed but it won't go below 2,500k.
Again if I turn ASC off the revs drop and it can be driven normally.
I've change the ASC switch, it makes no difference.
To clarify with ASC turned on the car increases in speed when driving.
The cc does work, I can increase and decrease speed but it won't go below 2,500k.
Again if I turn ASC off the revs drop and it can be driven normally.
Steve. H
Regular Member
As said before pingu it doesn't make any difference disconnecting it. So I think I'll have to take it to BMW & get them to plug it in and what's going on.
On another note, my passager window doesn't work. All I can hear is a slight clicking when pressing the switch. The clicking is coming from the fuse box area, which one is the relay I might need a new one.
On another note, my passager window doesn't work. All I can hear is a slight clicking when pressing the switch. The clicking is coming from the fuse box area, which one is the relay I might need a new one.
Steve. H
Regular Member
Goods news, problem fixed.
I replaced the ABS-ASCT module controller which is located behind the glovebox.
Just the electric window to fix now!!
I replaced the ABS-ASCT module controller which is located behind the glovebox.
Just the electric window to fix now!!
I was thinking about this the other day. So I'm glad it's sorted and you've updated us.
I was thinking it might be the controller that sits on the ABS pump. But this is a separate grey plastic box inside the car behind the glove box?
I was thinking it might be the controller that sits on the ABS pump. But this is a separate grey plastic box inside the car behind the glove box?
Have you got the part number for it?
Steve. H
Regular Member
Its a metal box about the size of a paperback. If you unscrew the glovebox it's bolted up to the left with a big white plug. I bought one with the same number but it made no difference so I bought another one with a different number and it worked perfectly. Maybe the previous owner didn't think it would make any difference.