Acellerator Cable Adjustment - RHD S4
09-07-2013, 06:25 AM
#1
Rennlist Member
Thread Starter
Photo of RHD accelerator cable setup needed please.
Hi, 1990 S4 - RHD.
I have been trying to follow some write-ups about how to go about adjusting all the cables on the throttle quadrant.
The first thing (REMAINING FOR ME) to adjust is the cable from the pedal which needs to be adjusted at the firewall so that "the compression spring on that cable, right at the throttle assembly" is about to compress with the pedal not quite engaging the kick down position.
I cannot find any adjustment on my firewall nor any compression spring at the throttle assembly. Probably looking at the wrong place???
As far as I can tell I have a continuous steel cable running from the pedal linkage (poking through the firewall into the cabin) to the quadrant on the intake. Shortly after the cable exists from below & behind the brake booster there is a banana shaped metal tube on one end of a sheath with a metal tube on the end of a second sheath (running to the intake end) that slots into it. (red arrow in picture). This is the only place where I could see that a compression spring might be utilised in the system I have.
Am I completely barking up the wrong tree or is this where the compression spring referred to in the adjustment instructions should be??
Myles
I have been trying to follow some write-ups about how to go about adjusting all the cables on the throttle quadrant.
The first thing (REMAINING FOR ME) to adjust is the cable from the pedal which needs to be adjusted at the firewall so that "the compression spring on that cable, right at the throttle assembly" is about to compress with the pedal not quite engaging the kick down position.
I cannot find any adjustment on my firewall nor any compression spring at the throttle assembly. Probably looking at the wrong place???
As far as I can tell I have a continuous steel cable running from the pedal linkage (poking through the firewall into the cabin) to the quadrant on the intake. Shortly after the cable exists from below & behind the brake booster there is a banana shaped metal tube on one end of a sheath with a metal tube on the end of a second sheath (running to the intake end) that slots into it. (red arrow in picture). This is the only place where I could see that a compression spring might be utilised in the system I have.
Am I completely barking up the wrong tree or is this where the compression spring referred to in the adjustment instructions should be??
Myles
Last edited by 928Myles; 09-09-2013 at 03:45 PM. Reason: Clarification
09-07-2013, 08:55 AM
#2
Rennlist Member
the first cable to adjust is the cable from quadrant to the throttle body.
loosen all others and start here.......then the pedal, auto tans then cruise.
loosen all others and start here.......then the pedal, auto tans then cruise.
09-07-2013, 03:56 PM
#3
Rennlist Member
Thread Starter
Malcolm,
probably worded badly in my OP. The throttle body cable is adjusted correctly. The next thing ( first now) I need to do is the pedal to quadrant cable which is where I either totally mis-understand what has been posted before or I have a different setup / am missing some parts scenario.
FWIW - All my cable adjusters other than the cable from pedal are in the middle of their range. The pedal to quadrant one is screwed almost right out.
Myles
probably worded badly in my OP. The throttle body cable is adjusted correctly. The next thing ( first now) I need to do is the pedal to quadrant cable which is where I either totally mis-understand what has been posted before or I have a different setup / am missing some parts scenario.
FWIW - All my cable adjusters other than the cable from pedal are in the middle of their range. The pedal to quadrant one is screwed almost right out.
Myles
09-08-2013, 08:22 PM
#5
Rennlist Member
never adjusted the pedal cable on a RHD car but on LHD cars theres an adjuster on the cable at the firewall........if its all the way out then either the other cable is misadjusted or the cable is worn out.
09-08-2013, 08:41 PM
#6
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This is the cable at the firewall that Malcolm is talking about.
By the way, mine is almost at the end of the ajustment range but everything works as it should.
By the way, mine is almost at the end of the ajustment range but everything works as it should.
09-09-2013, 03:52 AM
#7
Rennlist Member
Thread Starter
I have had a thorough look for an adjuster on the firewall. I cannot find one.
The cable guide (sheath) disappears below & behind the brake booster and I cannot see where it enters the firewall using a mirror. It would require removal of the brake booster to investigate further. I did remove the wheel liner to see if it came thought the side of the engine bay and entered the cabin by the washer reservoir but am fairly confident that is not the case either.
It would appear that the only place on my RHD system that the accelerator cable can be adjusted is at the throttle quadrant.
In a detailed post on how to adjust the cable GregBBRD refers to a compression spring at the throttle quadrant. My understanding of the function of the spring is so that you obtain full throttle just before the kick down switch is engaged and the spring compresses as the pedal is pressed further providing the necessary give in the system to allow the kick down switch to be pressed.
I am 99% sure that my system, as it stands, does not have this feature. If I adjust the cable such that the butterfly is fully open when the pedal is about to engage the kick down switch then there is no movement left to press the pedal further (without lots of pressure) and, as I understand it, a risk of breaking the cable.
Is there someone out there with a RHD S4 Auto able to take a photo of their throttle quadrant and the sheath junction I show in my first post so I can compare to mine. At least then I might be able to see where my problem is.
Thanks
Myles
The cable guide (sheath) disappears below & behind the brake booster and I cannot see where it enters the firewall using a mirror. It would require removal of the brake booster to investigate further. I did remove the wheel liner to see if it came thought the side of the engine bay and entered the cabin by the washer reservoir but am fairly confident that is not the case either.
It would appear that the only place on my RHD system that the accelerator cable can be adjusted is at the throttle quadrant.
In a detailed post on how to adjust the cable GregBBRD refers to a compression spring at the throttle quadrant. My understanding of the function of the spring is so that you obtain full throttle just before the kick down switch is engaged and the spring compresses as the pedal is pressed further providing the necessary give in the system to allow the kick down switch to be pressed.
I am 99% sure that my system, as it stands, does not have this feature. If I adjust the cable such that the butterfly is fully open when the pedal is about to engage the kick down switch then there is no movement left to press the pedal further (without lots of pressure) and, as I understand it, a risk of breaking the cable.
Is there someone out there with a RHD S4 Auto able to take a photo of their throttle quadrant and the sheath junction I show in my first post so I can compare to mine. At least then I might be able to see where my problem is.
Thanks
Myles
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09-09-2013, 06:35 AM
#8
Rennlist Member
Myles,
I cannot imagine the RHD configuration would be any different to the LHD but then it is a Porsche and they do a lot of seemingly dumbfounding things at times.
Not sure what you know and what you do not so bear with me, but there are two things you need to establish:
1. The idle switch actuates [ovbious if it does not -you will have no tickover].
2. When the throttle is fully depressed test to see if the butterfly will open some more. This is probably best done with the MAF out of position, someone in the cabin with their boot fully down, you then stick your pinkies over the butterfly and see if you can open it some more- if you can then the adjustment is all to ****-and this is quite a common occurence with these things [do not get your pinkies trapped!].
Your photo suggests the firewall adjuster is not there so good that someone with a RHD model sends you a pic of what is there [wake up you UK based punters and help the upside down kid!].
On my throttle, as others have said, the firewall adjuster is pretty much on full out- probably a sign of the cable stretching over the years [that or heavy driver hooves!].
The kickdown adjustment is such that as the cup engages the nipple the factory setting is to line it up and back it off a full turn, the "right way" to do it is to have it about 3 turns tight. to my liking the correct setting is when the car is doing about 110 kph [70 mph] a touch of light throttle pressure will get it to change into 3rd. If you have not done this - try it and report back. Then of course you can bypass the kick down altogether.
I have never tried to set the cruise control cable- never had a need to-it always seemed to work OK.
You might also take a look at where the cable connects to the foot pedal on your model. There has to be an adjustment somewhere in the system- perhaps they concocted something for your model in that area- much as I doubt it.
The adjustment of the main butterfly pull is critical- the butterfly should start to move just as soon as the quadrant starts to travel. If it does not then chances are you will not be be able to attain full throttle opening. This problem is more severe than some realise because the butterfly is actuated by a reverse cam and the butterfly opening is not directly proportional to cable pedal travel- thus the final stage of movement opens the butterfly quite a lot for what seems to be a relatively short amount of pedal [cable pull]stroke, thus probably why the full throttle switch opens at about 3/4 throttle because after that point it is pretty much all or nothing when adjusted correctly.
Good luck
Fred
I cannot imagine the RHD configuration would be any different to the LHD but then it is a Porsche and they do a lot of seemingly dumbfounding things at times.
Not sure what you know and what you do not so bear with me, but there are two things you need to establish:
1. The idle switch actuates [ovbious if it does not -you will have no tickover].
2. When the throttle is fully depressed test to see if the butterfly will open some more. This is probably best done with the MAF out of position, someone in the cabin with their boot fully down, you then stick your pinkies over the butterfly and see if you can open it some more- if you can then the adjustment is all to ****-and this is quite a common occurence with these things [do not get your pinkies trapped!].
Your photo suggests the firewall adjuster is not there so good that someone with a RHD model sends you a pic of what is there [wake up you UK based punters and help the upside down kid!].
On my throttle, as others have said, the firewall adjuster is pretty much on full out- probably a sign of the cable stretching over the years [that or heavy driver hooves!].
The kickdown adjustment is such that as the cup engages the nipple the factory setting is to line it up and back it off a full turn, the "right way" to do it is to have it about 3 turns tight. to my liking the correct setting is when the car is doing about 110 kph [70 mph] a touch of light throttle pressure will get it to change into 3rd. If you have not done this - try it and report back. Then of course you can bypass the kick down altogether.
I have never tried to set the cruise control cable- never had a need to-it always seemed to work OK.
You might also take a look at where the cable connects to the foot pedal on your model. There has to be an adjustment somewhere in the system- perhaps they concocted something for your model in that area- much as I doubt it.
The adjustment of the main butterfly pull is critical- the butterfly should start to move just as soon as the quadrant starts to travel. If it does not then chances are you will not be be able to attain full throttle opening. This problem is more severe than some realise because the butterfly is actuated by a reverse cam and the butterfly opening is not directly proportional to cable pedal travel- thus the final stage of movement opens the butterfly quite a lot for what seems to be a relatively short amount of pedal [cable pull]stroke, thus probably why the full throttle switch opens at about 3/4 throttle because after that point it is pretty much all or nothing when adjusted correctly.
Good luck
Fred
09-09-2013, 07:31 AM
#9
Rennlist Member
Thread Starter
Thanks Fred.
As far as I can tell the rest of the system works as it should. It is just the pedal to quadrant cable that seems to be amiss.
Myles
As far as I can tell the rest of the system works as it should. It is just the pedal to quadrant cable that seems to be amiss.
Myles
09-09-2013, 08:31 AM
#10
Rennlist Member
Myles,
Hopefully some right hooker can show you what they have- your photo looked a bit strange to my eye. I find it difficult to comprehend they would do something different but then the geometry may be completely different on the UK layout.
Regards
Fred
Hopefully some right hooker can show you what they have- your photo looked a bit strange to my eye. I find it difficult to comprehend they would do something different but then the geometry may be completely different on the UK layout.
Regards
Fred
09-09-2013, 03:34 PM
#11
Rennlist Member
Thread Starter
Fred,
on a RHD the accelerator pedal is pushed hard against the outside of the car. On a LHD it is much closer to the center. This means that the adjuster on the LHD sits out where accessible. It also means that if such an item is present on a RHD car then it must be below the brake booster - a very difficult to reach position.
It seems to me that Porsche would not position such an item there (I hope).
Myles
on a RHD the accelerator pedal is pushed hard against the outside of the car. On a LHD it is much closer to the center. This means that the adjuster on the LHD sits out where accessible. It also means that if such an item is present on a RHD car then it must be below the brake booster - a very difficult to reach position.
It seems to me that Porsche would not position such an item there (I hope).
Myles
09-09-2013, 03:51 PM
#12
Rennlist Member
Fred,
on a RHD the accelerator pedal is pushed hard against the outside of the car. On a LHD it is much closer to the center. This means that the adjuster on the LHD sits out where accessible. It also means that if such an item is present on a RHD car then it must be below the brake booster - a very difficult to reach position.
It seems to me that Porsche would not position such an item there (I hope).
Myles
on a RHD the accelerator pedal is pushed hard against the outside of the car. On a LHD it is much closer to the center. This means that the adjuster on the LHD sits out where accessible. It also means that if such an item is present on a RHD car then it must be below the brake booster - a very difficult to reach position.
It seems to me that Porsche would not position such an item there (I hope).
Myles
That is why I suspect such may be placed somewhere else for accessibility. Give Jon or Hilton a personal message [they ar ealso in upside down land] and ask them for their take as they must have similar setups to yours.
Then of course there is Roger the dodger with the SE he stole from the UK recently!
Regards
Fred
09-09-2013, 05:01 PM
#14
Rennlist Member
Thread Starter
Thank you Oliver.
That is the conclusion I am coming to. What I need to figure out is how the RHD system allows for the fully open throttle when the pedal is right down (sans kick down switch) and then still has movement to enable kick down to be activated. A photo in the same area as my OP photo would be great as this is the only place in the system where I can see a compression spring might need to be.
Myles
That is the conclusion I am coming to. What I need to figure out is how the RHD system allows for the fully open throttle when the pedal is right down (sans kick down switch) and then still has movement to enable kick down to be activated. A photo in the same area as my OP photo would be great as this is the only place in the system where I can see a compression spring might need to be.
Myles
09-09-2013, 05:15 PM
#15
here the photos:
Photo 1, solid cable guide (tube) with throttle cable from accelerator. Essentially the same view as your photo.
Photo 2, throttle cable quadrant end with the two adjustment threads.
I'll climb underneath to have a look from below, but I don't think there is anything to be seen.
Let us know if you need anything else.
Photo 1, solid cable guide (tube) with throttle cable from accelerator. Essentially the same view as your photo.
Photo 2, throttle cable quadrant end with the two adjustment threads.
I'll climb underneath to have a look from below, but I don't think there is anything to be seen.
Let us know if you need anything else.