A Guide To Adjusting The Throttle Cable

[msprince]

First of all you will need 2x 12mm spanners and a set of adjusters.

Locate the throttle body, you can follow the cable to it.

This it the cable you want.

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This is how much free play i had.

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Now you will need to loosen the top nut off, until you can remove the cable form its housing.

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I found it is easier to pull the cable upwards like so.

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Then wind the second nut upwards (away from throttle body).

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Wind the nut up about a quarter of the way then put it back into the bracket and pull the cable away from the throttle body to tension the cable and check the free play, if there is still some there wind the nut up a bit more and re-tension and re-check.

You do not want to adjust it to the point where the throttle arm is not sitting in a "rest" position otherwise your car will idle higher.

Once you have got adjusted the free play out, wind the top nut back down to lock it off.

Now go and reap the benefits.

[eddieinvader]

How much benefit have you seen in the car since doing this :D

[Jamesbelfast]

There always has to be some free-play in the accelerator cable.

The reason being it allows for expansion and contraction due to temperature changes. Plus the throttle lever or body needs to be able to move freely during cold idling. Also it prevents the cable from being over-stretched a full throttle opening.

If adjusting the throttle cable slacken off the adjustment - depress the accelerator pedal to the floor and then adjust the nuts to take up the slack - then back off about 6-8mm to allow for free movement.

Shortening the length of the cable will make little or no difference to throttle response. It not the time it takes for the throttle to move is important its how quickly the engine can respond that matters.:)

[KPARRIS-JONES]

I think the theory is that too much slack means too much energy and time is wasted in getting the cable to take it up. From what I have seen, peoples time at Santa Pod have been noticeably better after the cable has been adjusted.

Also, the expansion that could take place wouldn't equate to that amount, if it did I would be seriously concerned about what materials were being used to make my engine.

[nrgizerbunny]

There always has to be some free-play in the accelerator cable.

The reason being it allows for expansion and contraction due to temperature changes. Plus the throttle lever or body needs to be able to move freely during cold idling. Also it prevents the cable from being over-stretched a full throttle opening.

If adjusting the throttle cable slacken off the adjustment - depress the accelerator pedal to the floor and then adjust the nuts to take up the slack - then back off about 6-8mm to allow for free movement.

Shortening the length of the cable will make little or no difference to throttle response. It not the time it takes for the throttle to move is important its how quickly the engine can respond that matters.:)

I don't agree with any of this and I think its **** advice. The main reason its slack is because they haven't got the time to do it properly in burnaston where they made the car.

the cable is inherently flexible so if it expands and contracts , the radius of the arc will change.

a tight throttle cable means you've got no deadspot, the first 10mm of travel might be free play on a slack cable. Once adjusted it immediately opens the throttle valve.

As for over stretching err once again the sleeve will flex.

[FoxX]

The only problem I had with it too tight is that if I came off the throttle too quickly on deceleration the car would jer*k somewhat.

But on the other hand its nice having the extra precision though as it made hill starts easier when I first bought one as. Basically because its the best insulated car i've ever had and the TS is suprisingly quiet in the cabin on idle so I couldnt judge how much juice I was giving it without checking the revs (kept stalling lol).

[Uber_Luke]

I definitely noticed a difference once ricc did mine, not only at santa pod, but on motorway driving aswell

Once again people are quick to post negative statements and theories when people offer genuine advice / improvements.

[CorollaD4D]

do you think this is worth attempting on my diesel?

i mean on all diesels the throttle response is quite numb on the 2.0L engines, even my mates mk5, so might be worth trying to sharpen it up a little?

If adjusting the throttle cable slacken off the adjustment - depress the accelerator pedal to the floor and then adjust the nuts to take up the slack - then back off about 6-8mm to allow for free movement.

6-8mm? id be very worried if needed that much slack to work properly or to allow for heat expansion/contraction!

[msprince]

I noticed a difference, nothing major but it feels more precise.

Since i did it to my car i would advise other people getting it done.

[nrgizerbunny]

I think the diesel is Drive By Wire not throttle. I'm not familiar with the D4D but I'd imagine you would vary the fuel injected. Thus I don't think you have a cable to adjust?!

Just to clarify the linear expansion business.

from this website the coefficient of expansion of steel is 13e-6m/m/K. If the steel was a metre long and the temperature increased by 60C, the cable would grow by 0.78mm

[CorollaD4D]

you're probably right on the drive by wire business, it would make sense. thanks for clarifying the expansion issue.

[Clawliger]

Considering that throttle cables are a service item. That should be checked at certain service intervals, probably on higher intervals. And being a technician i can say that hardly any of the t sports would of had there throttle cable checked during a lower mileage serviceing i.e dealer servicing. Therefore most tports will need there throttle cable adjusting purely down to age. I adjusted mine, the week i had it. Its allways worth doing. I do also believe that whoever posting the negative comment previusly doesnt seem able to prove his "theory"

[KPARRIS-JONES]

I'll go off and do this on my GTi if it stops trying to blow itself up.

Very slack cable, never touched after 21 years of motoring :o

[Jamesbelfast]

The most important aspect of adjusting a standard throttle cable system is to ensure the throttle is fully open when the accelerator pedal is fully depressed. In other words adjustment should be made with the pedal to the floor. If the cable is too slack then the throttle mechanism won't fully open. If too tight then the cable will be stretched or the mechanism stressed.:)

[KPARRIS-JONES]

I seriously doubt you can stress it all that much. It's a steel cable... People make bridges out of these things :P

However you are right in so far as if it is too tight then you risk the throttle being open slightly when it shouldn't be. Too loose and it won't open fully.

[Uber_Luke]

To avoid tightening it up too much, once you have done it, start the engine and if the idle is affected ( idling above 800rpm when fully warmed up in the T sport's case) then you have done it too much.

[Clawliger]

The most important aspect of adjusting a standard throttle cable system is to ensure the throttle is fully open when the accelerator pedal is fully depressed. In other words adjustment should be made with the pedal to the floor. If the cable is too slack then the throttle mechanism won't fully open. If too tight then the cable will be stretched or the mechanism stressed.:)

If you read the title and the instructions you will realise that this is a guide to adjust the throttle cable. Not stretch the cable or cause inproper operation of the throttle body.

[eddieinvader]

I did this a few months back as stated and still had a little play even when fully adjusted it has been bugging me the throttle was much more responsive but still needed that something, finally found it today in the shape of a rubber tap washer cut it on one side to get it past the cable and it sits behind the metal stop end of the throttle cable at the back of the pedal just right, throttle response is instant.

While I was at it I adjusted the clutch pedal down a bit on the screw at the top of the pedal it has felt a bit high for a while, just thought I would mention it as the car feels much better for these simple tweeks, just goes to show you don't have to spend a fortune to get results

[SanaYusuf]

Just done this on my T-sport aswell as giving the throttle body a good clean and it has really improved pedal feel and response.

Just thought I should bring this to people's attention as it's worth while and free.