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Throttle/Bowden cable adjustments

 
Old 05-30-2013, 12:53 PM
  #16  
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ok.....wait one second here..... lol

The "bowden" cable is just the "Kick down" cable??? So, adjusting this cable only really effects when the kickdown kicks in??? I thought adjusting this cable may give me better shifts.

So, if this just adjust the kickdown....and I have a kickdown switch by my seat, I really don't even need that cable hooked up?
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Old 05-30-2013, 12:58 PM
  #17  
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Originally Posted by Jeff928S4 View Post
ok.....wait one second here..... lol

The "bowden" cable is just the "Kick down" cable??? So, adjusting this cable only really effects when the kickdown kicks in??? I thought adjusting this cable may give me better shifts.

So, if this just adjust the kickdown....and I have a kickdown switch by my seat, I really don't even need that cable hooked up?
No,no.
This cable pulls a lever at the transmission which allows the pressure control valve to do its thing regarding the timing of gear shifting. 'Kickdown cable' is just its name. Not directly involved with kickdown switch. This cable DOES need to be set right for timing of gear shifts. If done, the improvements you have seen will get even better.
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Old 05-30-2013, 12:58 PM
  #18  
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Originally Posted by MainePorsche View Post
If you can't get the kickdown (Bowden) cable off the lever at the ball/cup union, you can do this
I can get the ball to pop off the lever, I just can't get the ball part to turn so it will adjust on the cable. I held the cable with vicegrips and tried turning the small nut at the end of the ball part, but the cable kept slipping out of the vicegrips.
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Old 05-30-2013, 12:59 PM
  #19  
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Originally Posted by MainePorsche View Post
No,no.
This cable pulls a lever at the transmission which allows the pressure control valve to do its thing regarding the timing of gear shifting. 'Kickdown cable' is just its name. Not directly involved with kickdown switch. This cable DOES need to be set right for timing of gear shifts. If done, the improvements you have seen will get even better.
That's what I figured.

Damn - now I want to get it adjusted (it just needs to be a tad tighter) ever more!!!
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Old 05-30-2013, 01:03 PM
  #20  
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Originally Posted by Jeff928S4 View Post
I can get the ball to pop off the lever, I just can't get the ball part to turn so it will adjust on the cable. I held the cable with vicegrips and tried turning the small nut at the end of the ball part, but the cable kept slipping out of the vicegrips.
Spray a tad of penetrating oil like PB Blaster on the nut. Don't crimp down on the neck with a vice grip for you will not allow the bolt end of the cable to turn within it. Use a 7 mm wrench on the proximal end of the neck of the cup. Use a 8 mm wrench on the lock nut. It is simply counter holding. You may have to sneak a little PB into the neck of the cup. Hopefully you have not crimped it to deformity.
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Old 05-30-2013, 01:11 PM
  #21  
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Ahhhhh - I see what I was doing wrong. I thought the whole ball section moved all at one around the threads of the end of the cable.

Gonna give it another try tonight!
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Old 05-30-2013, 01:15 PM
  #22  
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Originally Posted by Jeff928S4 View Post
Ahhhhh - I see what I was doing wrong. I thought the whole ball section moved all at one around the threads of the end of the cable.

Gonna give it another try tonight!
Well there ya go !
Sounds like you'll get it done.
The process will require probably several test drives. Loosen the BOWDEN cup 5 turns. Re-attach and take it for a drive. You'll know when your timing is right. Make take several loosening/tightening runs.
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Old 05-30-2013, 02:33 PM
  #23  
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Went out and just tried to get it to move with a adjustable wrench and an 8 mm wrench - no go. Finally found a 7mm wrench (why do I have four or five 6/8/10mm, but only one 7mm - lol). Gonna try again!
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Old 05-30-2013, 05:57 PM
  #24  
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Finally got the bowden cable adjustor to move. Tightened it as far as it will go. The last few threads on the bolt that goes into the ball end are stripped, so I can't get it any tighter.

Quick question....

In re-reading the order to adjust the cables, the suggestion is to adjust the "throttle" cable first. It say that is the cable that "goes around the wheel". Is this "wheel" the one that the pedal cable goes around? If the first adjustment is the "to pedal" cable, it makes sense that tighten it would loosen the bowden cable and visa versa.

As for this "click".....I was adjusting the "throttle" cable. Does the "click" come from movement of the cable or movement of the metal plate it attaches to? The "click" happens best when the "throttle" cable is as loose as possible, but as you tighten the cable, it makes it hard to get the click by moving the assembly a bit - it would seem one needs to tighten the "to pedal" cable to get the metal plate to rotate to the left, thus getting closer to the "click".

When I adjusted the bowden cable, I loosened all the other cables first, then went in order 1 - "throttle" 2 - Bowden 3 - "to pedal", then the cruise.......but now, the car runs like before (****ty).

I know the "to pedal" cable is a lot less tight than before (I set it AFTER doing the "throttle" cable). When I did it the first few times, I started by tightening the "to pedal" cable, then found the click with the "throttle" cable second - and the car ran awesome???

Going back out to fiddle with it some more......
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Old 05-30-2013, 06:16 PM
  #25  
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Jeff,
The throttle cable is the cable on the same lever arm as the transmission cable. It is its 'mirror image'. With the throttle cable detached, when you give it slight traction with your left hand you will hear a click. This click is from the TPS, throttle position sensor. As soon as you hear the click, this is where you want to set the cup to the ball. That is adjustment (1). Then with the throttle cable adjusted, you want to set the bowden cable cup to ball at this point. This is adjustment (2). Then set the pedal cable cup to ball being mindful not to let the throttle cable move. This is adjustment (3). Then set the cruise cable with laxity at this point. This is adjustment (4).

But YOU are not done. Start your engine and go for a drive and note the timing of your shifting. Does it feel like you're winding up to high for a given speed ? Or, does it feel like you're shifting a little to soon ?
Post back when you get to this point.
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Old 05-30-2013, 06:42 PM
  #26  
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This picture might help. It shows a peek view under the intake of the open mouth of the throttle with the throttle plate inside to the left and the end of the throttle cable on on the lever (or bellcrank) that moves the center shaft opening the plate opposed by the coiled spring. If you removed the air filter box bottom and MAF, this is what you would see.




Not shown above is the idle/WOT switch box, mounted on the other end of the throttle plate shaft, further to the left. Here's a pic with the throttle housing removed from the intake showing that switch on the other side of the throttle housing attached to the other end of the throttle plate shaft (note: throttle plate itself has been removed but you can see the shaft).




As the throttle plate rotates, pulled open by the throttle cable, and moves slightly off the idle stop, you should hear a faint "click" with only a 1/4" inch or so of cable movement. Then, if you release the throttle cable slowly and allow the spring on the throttle to pull the throttle plate closed, you should hear another faint "click". If you don't hear a click in either one of these directions, loosen the cable adjuster until you get totally reliable clicks in both directions. I haven't read all of the various recommendations here, but that's what I do, Then I adjust the section of cable going to the pedal to get nearly all the slack out. The process is iterative, so I recheck the reliability of the idle switch click again and readjust if needed until everything has minimal slack but the definite click is still reliable. At the same time make sure there is a fair amount of slack in the cruise control. You don't want it affecting the idle position at all, so it needs a good amount of slack. The cruise will have no trouble pulling out the slack when it activates. Finally I adjust the Bowden length. There are lots of ways this all could be done but this works for me. It may be more logical to adjust the pedal section first or follow some other steps, but I haven't had to.

The yellowish/white plastic wheel that others have pictured is behind the throttle. The throttle cable routes around that wheel so the cable direction changes 90 degrees from going across the back of the motor to going straight forward to the bellcrank. If the cable is allowed to go very slack for some reason, it could come off that wheel. But you would know. If it does, removing the air filter box and MAF will give you access to fix that. Anyway, that's just FYI, as it is not relevant now.
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Old 05-31-2013, 12:23 PM
  #27  
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Great info folks - thanks!

Farted around with it again last night (hands now full of blisters from adjusting those plastic blocks).

I have come to the conclusion that it doesn't matter which cable you adjust first (between the "to pedal" or the "throttle" cable), as they both basically are "one cable". Pressing the accelerator pulls the "To pedal" cable, which turns the metal mechanism, which pulls on the "throttle" cable. The goal is to make sure as soon as that cable starts to move, it clicks the TPS and when it returns to it's original position, it clicks the TPS again.

In doing more searches, I have found a few threads that say to start with the "to pedal" cable, then the "throttle" cable; yet others say to do it in the reverse.

An excerpt from one of those threads....

There are either three or four cables:
- pedal to quadrant
- quadrant to throttle
- cruise control to quadrant
- quadrant to automatic transmission

The throttle pedal can be adjusted - different attach holes at the base.

The cable from the pedal should be adjusted first - no tension, just a tiny bit of free play.
Next, the cable to the throttle - same adjustment.
Then the transmission cable (automatics only). Some folks like a bit of tension - you can adjust the shift points with this.
You don't often need to adjust the cruise control cable.

It is important that the idle switch and the WOT switch both work properly.
Idle Switch - zero Ohms with your foot off the throttle pedal, infinite Ohms as soon as you move the pedal.
WOT Switch - infinite Ohms until you get to about 2/3rds throttle, then zero Ohms.

BTW - you can check the idle switch while driving on any 928 with the digital dash. Set the dash on instant fuel economy. Drive at highway speed (over 1500 RPM) and lift your foot completely. If the mileage goes to 90 mpg (USA cars) or zero (RoW cars), the idle switch is closed. When you barely open the throttle, the fuel economy must drop slightly to show that the switch is opening.



So, as of right now, I know I am not getting the second "click". Car is performing like before and that "burp" I mentioned is obviously the lack of the idle switch closing. When I let off the gas while driving, the car's RPM's rise ever-so-slightly and the car makes a noise as if it is exhaling.

I italicized the part above about using the digital dash to check your idle switch. I went out last night and did the trick and as soon as I let off the gas, the number on the display just starts to slowly drop. I believe it is supposed to drop instantly to either 0 or 90 (depending on the car).

Basically, when I release the gas pedal, should the idle switch click and then BAM, there is no gas entering the engine/throttle plate is closed? This is why the digital dash will show you burning 0 mpg? As I mentioned, when I release the pedal completely, the display will slowly drop, which tells me that even with the pedal completely released, gas is still entering the engine?

Going back out again to try and line that click back up. I am noticing that when you pull the throttle plate to the left to get the click, then release it to get the click - that's fine and dandy, but when you actually push the accelerator, the plate doesn't "snap" back as far as if you do it by hand. The long run of the "to pedal" cable seems to leave a ever-so-slight discrepancy.
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Old 05-31-2013, 12:40 PM
  #28  
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"Basically, when I release the gas pedal, should the idle switch click and then BAM, there is no gas entering the engine/throttle plate is closed? This is why the digital dash will show you burning 0 mpg? As I mentioned, when I release the pedal completely, the display will slowly drop, which tells me that even with the pedal completely released, gas is still entering the engine?"

If you are over 1500 RPM, your idle switch appears to be inoperative, most likely due to maladjustment of the cables. The mileage should go to 90 MPG (not 0 MPG) when you lift completely above 1500 RPM, as the LH cuts fuel flow completely.
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Old 05-31-2013, 01:46 PM
  #29  
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Originally Posted by WallyP View Post
The mileage should go to 90 MPG (not 0 MPG) when you lift completely above 1500 RPM, as the LH cuts fuel flow completely.
My car is a Canadian version, does that mean it's supposed to drop to 0?

Went out at lunch and tightened the throttle cable and loosened the "to pedal cable" (I figure that will help it "bounce back/snap" so I get the second click when releasing the pedal).

Now, when I lift my foot completely, the MPG dropped from 39 (for example) to 10, then instantly to 0.0. The next few times it didn't do it, then it did it again. I must be juuuuust off on the adjustment.

I need to put someone in the seat and press the pedal so I can hear if it is clicking when it is released with the pedal vs moving the throttle under the hood - that way I don't have to keep adjusting, then driving, then adjusting....
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Old 05-31-2013, 02:01 PM
  #30  
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Originally Posted by Jeff928S4 View Post
...- that way I don't have to keep adjusting, then driving, then adjusting....
That is what I did, and it worked out perfectly.
Luke, patience you will...
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