[968Syncro]

So, one of the pet peeves with the Tiptronic is it doesn't know the car is going uphill. So it tends to lug in a lower gear, 3rd or 4th. I have been in the habit now for years of just flicking the tip over and hitting a lower gear. The lugging isn't a problem/risk for the engine, but it is tougher to accelerate in the lower gear.

So today I decided to punch the accelerator pedal down, which of course has always worked as well to get a lower gear. And low and behold, the engine reved nicely and the pedal stay on the floor. Yikes! Turned the key one notch to kill the engine while in drive, of course not so far as to lock the steering wheel, and then shifted into neutral and braked to a stop.

When I reached down, in fact the lever behind the pedal was glued to the floor. Open the hood, and the cable had come off of the idler pulley. I pulled on the cable to get it back on the idler pulley, and that was fine, it went back on. But oddly, something clicked like the throttle levers on the throttle body. Anyway, the pedal came back up, and I tried a few times. Was only a mile from home so I proceeded.

I knew for some time that the cable was a bit loose. So I adjusted it now, and a bit of lubrication. Punched it a dozen times from the drivers seat and all seems to be well.

The missing part, where I could use some advice, it apparently the levers on the throttle body got stuck. I think even if the cable comes off the idler, the springs on the throttle body should return the car to idle. I've examined a bit, and everything appears to be intact. Seems perhaps some lube may be needed, but other than some WD-40 on the shafts, if there something else to do or lube?

Roland

Partial Post: Please Login or Register to read the full post.

[968Syncro]

And, yeah, just thinking about it some more. I essentially never slam the pedal to the floor, when seeking some speed I usually go gentle, and find the speed without a hard floor push. I wonder if this time I got the throttle levers in a position where they rarely go, and there was some crud that got invoked and jammed those throttle levers right on the body. Not sure, just an idea.

Roland

Partial Post: Please Login or Register to read the full post.

[flash]

there is a screw beneath the pedal that will provide a stop so that it doesn't overrun the travel

Partial Post: Please Login or Register to read the full post.

[Ryan]

"Little known fact" the pedal belongs all the way to the floor!!!!!!

Partial Post: Please Login or Register to read the full post.

[rhudeboye]

'Ryan' "Little known fact" the pedal belongs all the way to the floor!!!!!!


LOL. I knew that

Partial Post: Please Login or Register to read the full post.

[ds968]

ok. tapping into the collective wisdom of the forum : there are two schools of thought - 1) the throttle cable should be set as tight as a violin string , so at a max tension, just as long as it's not pulling the lever up, of course Or, 2) it should have a little slack - maybe a 1 or 2 mm "give" if you press the cable with your finger . So which is it ? And what's the rationale in support of either 1) or 2) setups ?

Personally I'd opt for 1) to eliminate even a 1/100 of a sec. delay in acceleration the moment you as much as barely touch the gas pedal ..and then floor it .:-)

Partial Post: Please Login or Register to read the full post.

[Bulti]

I would say that any slack is to be avoided because you want the throttle valve to react instantly. At the same time you want the valve to be able to close 100% when braking etc. I can imagine that the cable shrinks or stretches a bit when it get heated up or cooled down. So I guess a tiny bit of slack would be ideal.

Partial Post: Please Login or Register to read the full post.

[ds968]

Hmm , the hot / cold impact on that cable never even crossed my mind . But I would imagine that should be such a minimal effect, it probably does not really make much of a difference .. Of course my assumption could be wrong, it certainly would not be the first time , lol...

Partial Post: Please Login or Register to read the full post.

[94SilverCab]

Since Flash can't resist adjusting the tension perfectly on any 968 he ever spies, I would guess that yours is just about perfect. If I recall, there is just the slightest bit of play in the cable.

 

Jay

Partial Post: Please Login or Register to read the full post.

[ds968]

Ha, I messed around with certain components of both cars long after flash last worked on them.. Not to mention how many times my mechanic worked on them in the meantime . One of those things I played with is the throttle idle screw for example , but I think I also may have adjusted the cable to get rid of what I thought was just a bit too much slack. They now both appear to have no slack whatsoever unless you slightly push it in which case I'd does give in a couple of mm without disturbing the throttle lever from its resting position.

Partial Post: Please Login or Register to read the full post.

[Big Carl]

I would think you would want to adjust the cable in the WOT position, no? 

If you have it tight at idle, it way be overly tight at full throttle resulting in cable strain and possible breakage.

I would be OK with a little slack at idle, as long as the throttle valve is opening all the way without excessive tension.

 

I'm sure someone with a manual can give a definitive answer...

Partial Post: Please Login or Register to read the full post.

[ds968]

I adjusted it at it closed / idle position,  not at wot.   That looks like a braided steel or other metal cable, what kind of stress can cause something that strong to break ? 

Partial Post: Please Login or Register to read the full post.

[az968]

The massive torque of a 968 engine with your foot in it!

Partial Post: Please Login or Register to read the full post.

[Big Carl]

I have had clutch cables break in my old 924 - a combination of age, stress and heat.

 

I don't know if the cable itself would fail in our 968, but I would be weary of the idler wheel, especially considering what age and heat will do to plastic...

 

Is the pedal stop adjustable? I am not near my car to look.

I guess ideally you would want to get your throttle valve to close all the way, then pull out *Most* of the cable slack (leaving enough that engine movement and temp changes don't effect your idle). Then I would adjust the pedal stop to achieve the ideal throttle valve position at WOT with the pedal bottoming just before the throttle valve hits limit.

Partial Post: Please Login or Register to read the full post.