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As the title suggests, one of the annoyances I've had with my car is the sticky throttle. It will not transition smoothly from idle or off-idle to accelerate. You push on the pedal, it's starts smoothly, then hits a 'bump' and sticks for a second, then all is smooth again. It makes a smooth acceleration across an intersection difficult.
I pulled the cable and it moves very smoothly through it's housing. The pedal is smooth also. However, the linkage where the cable connects has lots of sideways movement - about 1/4" where the plastic roller rides on the plate. This car only has 45XXX miles on it and I'm dumbfounded how the linkage could wear out so quickly, if that's what's happening. Is sideways movement normal? Please take a look at the pics (the second pic is with my finger pushing the plate straight. The spring in the linkage pulls it at an angle).





Aaron
1976 TR7 FHC (an ongoing project)

What type of carbs are on the engine ? Are the return springs maybe too heavy - that will make for sticky throttle - and causes extreme wear.

They are Zenith-Strombergs and there's two return springs. One on the throttle pedal itself and a small but stout one on the end of the linkage. I'm thinking the the pedal spring might be enough spring action by itself. Maybe not. I've got a box of various throttle springs and what not around here - I might have to tinker with this.
Anyway, I take it the sideways movement is NOT the norm?

Aaron
1976 TR7 FHC (an ongoing project)

AAron, I have had this problem with a few cars. BMC used to oil the
cable of the Mini, every service, which meant, in our dusty climate,
they were always sticky, & "jerky".

On the 7 I find I have to do a good job of lubricating the throttle
pedal pivot, about once every two, or three years, to prevent the
worst effect. It starts to squeak when service is required.

However, with the cheep throttle cables we get today, there is
another problem. The 8 came with a cable which has an inner plastic
sheath, lining the steel outer. This never gets sticky, but I am
unable to find this quality cable in Queensland, or where the PO got
it down south.

My 7 suffers from a sticky throttle about every 3 or 4000 Km, with
its cheep unlined cable. Lubricating the throttle spindles, & the
cable with WD 40 will "fix" this for a couple of hundred Km only.

For a semi permenant fix I have to remove the outer cable, sliding
it off the carb end. I find it is always oily, from the carb end, to
some extent, & the oil has picked up dust. I clean the oiliness off
the inner, with a petrol soaked rag, & make sure it is thoroughly
dry.

I then wash out the outer with plenty of petrol, degreaser, & water,
blown dry, with air. After this I "puff" some graphite powder
through the thing with a squeeze bottle, & reinstall.

As I reinstall the thing, [for the 15Th or more time] I always make
the same idle threat, to put more effort into finding a good quality
cable for the old girl.

Hasbeen

Ps. No my linkage, at 160,000Km is not loose, or sloppy, although
another 7s, I owned recently, was at less than 100,000 Km.

actually this is know problem. i found this out first on the triumph dolomite forum. it was a poor design (metal on metalat pivoting point). you can use a throttle plate from a later tr7 with a little work. The hole at the pivoting point gets enlongated. if you need a late model throttle plate i can send one.

by the looks of the first picture, it's going come a part soon.


Clifton davis
Rockford,IL


<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by TR7Aaron</i>







Aaron
1976 TR7 FHC (an ongoing project)

<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

<b>"GETTING SPEED OUT OF A LOW POWERED CAR IS OFTEN MORE REWARDING, THAN WITH TIRE-SMOKING BRUTES" </b>

Clifton,
Email sent. Thanks.

Aaron
1976 TR7 FHC (an ongoing project)