Throttle linkage

sonscar · Postby **sonscar** » 10 Dec 2014 19:53

I am still ironing out some bugs/undesirable traits from my car.The throttle action can only be described as "sticky".The first few mm of travel is very stiff and then once the initial jerk is over it works ok,but as this corresponds with setting off and 30mph it is annoying verging on difficult to drive.There appears to be no undue wear on the parts but the orientation of them seems awkward.Is there a definative guide to the setting up of this cable/lever throttle operating mechanism for twin SU's.Thanks in advance,Steve..

busheytrader · Postby **busheytrader** » 10 Dec 2014 20:49

Hi,

Have you disconnected the cable from the carbs to see which part is sticking. I had something similar. Removing the cable from its sleeve, coating it in LM grease and refitting it had it sorted. The bottom 3" had run dry and corroded leading to stiction.

Adam

TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991 courtesy of S&S V8 conversion kit (built not bought) and big brake kit.

Hasbeen · Postby **Hasbeen** » 10 Dec 2014 23:14

Cable lubrication can also cause the same problem.

I don't know what BMC did to lubricate the throttle cable on the original minis at each 1000 mile service, but it caused this sticky throttle problem a week or so later.

I think it must have been oil, & it collected dust & became sticky. In those days cables had an inner sheath, & did not require lubrication. I found taking the inner cable out, & washing it & the sheath out with petrol fixed the problem, until the next service.

Hasbeen

Cobber · Postby **Cobber** » 10 Dec 2014 23:31

if you clean the cable as Hasbeen suggests and then dry lubricate it with graphite power, you have a lubricated cable that won't attract dirt etc.

"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"

80'Triumph TR7, 73'Land Rover (Ford 351. V8),
'89 Ford Fairlane
'98 MG-F, 69'Ford F250.

sonscar · Postby **sonscar** » 11 Dec 2014 19:42

First thought was the cable but that is nice and free.The angle of the rod that connects the cable quadrant to the throttle quadrant seems very acute and needs a lot of force to get it to move.Searching posts on this I will probably try Beans' fix with some ball joints instead of the bit of bent wire.Steve..

Beans · Postby **Beans** » 12 Dec 2014 15:33

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by sonscar

... The angle of the rod that connects the cable quadrant to the throttle quadrant seems very acute and needs a lot of force to get it to move ... <hr height="1" noshade id="quote"></blockquote id="quote">
That's probably the reason for most of the so called "sticky" throttle action.
The factory linkage is a soft metal alloy which wears pretty quickly,
and combined with the sharp operating angle it feels as if the throttle is sticking when you press the pedal from idle.

My solution Steve is referring to ...

After fitting it the pedal response was very smooth, despite the fact that the ball joints used were discarded from 't Kreng because they were a little worn.

<center>

1976 TR7 FHC (needs some TLC ...)
1980 TR7 DHC (my first car, a.k.a. Kermette)
1981 TR7 FHC (Sprint engined a.k.a. 't Kreng
[url="http://www.tr7beans.blogspot.com/"]My full Blog[/url]</center>

TR Tony · Postby **TR Tony** » 13 Dec 2014 06:48

That's very neat Theo. Did you make that up from a short length of threaded rod with a ball joint at each end? What have you done to replace the retaining clips that hold the link rod on the factory part?

Tony

1981 TR7 FHC Cavalry Blue
1980 TR7V8 DHC Jaguar Regency Red - sadly sold!
1977 TR8 FHC EFI Factory development car Inca Yellow

Beans · Postby **Beans** » 13 Dec 2014 09:01

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by TR Tony

... Did you make that up from a short length of threaded rod with a ball joint at each end? What have you done to replace the retaining clips ... <hr height="1" noshade id="quote"></blockquote id="quote">
I used this linkage from the Weber set up from 't Kreng, only shortened it a bit ...

And as you can see the linkage is held in place by (lock) nuts.

<center>

1976 TR7 FHC (needs some TLC ...)
1980 TR7 DHC (my first car, a.k.a. Kermette)
1981 TR7 FHC (Sprint engined a.k.a. 't Kreng
[url="http://www.tr7beans.blogspot.com/"]My full Blog[/url]</center>

sonscar · Postby **sonscar** » 22 Dec 2014 10:55

Following Beans' example I purchased this

This was an off the shelf Weber part and as such was relatively expensive.Fitting involved removing the carbs again after the waterpump repair but was otherwise straightforward.The action is so improved that I have had to relearn to drive the TR7 again.Previously you subconciously pressed hard on the first part of the throttle to overcome the initial reluctance to move,now this results in overrevving and subsequent stares from pedestrians.Never professing to be a good driver it has taken a few drives to get used to.Must have been accounting that prevented this from being installed from new.Wothwhile modification?Definately,Steve..

TR Tony · Postby **TR Tony** » 22 Dec 2014 11:07

Thinking of this myself Steve, as my 7 suffers from the same problem.I am going to have carbs off soon to fix a small leak (!) so it would seem an ideal time to try this.

Off the shelf part? I have seen a few similar parts on eBay but where did yours come from? Any modifications needed?

Tony

1981 TR7 FHC Cavalry Blue
1980 TR7V8 DHC Jaguar Regency Red - sadly sold!
1977 TR8 FHC EFI Factory development car Inca Yellow

sonscar · Postby **sonscar** » 22 Dec 2014 20:40

Came from Ebay seller,not sure which one but the shortest lh/rh thread linkage available(44mm?)Bolted directly in place of the bent wire and adjusted to the same length.Completely altered the throttle feel,now veery smooth.Steve.P.S cost Â£15.00 probably could have been done cheaper but sometimes the small problems acquire an unjustified massive response.

Beans · Postby **Beans** » 23 Dec 2014 09:40

Looks like the one Webcon sells.

<center>

1976 TR7 FHC (needs some TLC ...)
1980 TR7 DHC (my first car, a.k.a. Kermette)
1981 TR7 FHC (Sprint engined a.k.a. 't Kreng
[url="http://www.tr7beans.blogspot.com/"]My full Blog[/url]</center>

TR Tony · Postby **TR Tony** » 24 Dec 2014 06:37

Thanks Steve, I shall get one. I see you can buy the rod & ends as separate parts but not much cheaper than the whole assembly. It will be worth it!

Tony

1981 TR7 FHC Cavalry Blue
1980 TR7V8 DHC Jaguar Regency Red - sadly sold!
1977 TR8 FHC EFI Factory development car Inca Yellow

andyf · Postby **andyf** » 27 Dec 2014 09:33

I've just ordered one myself, the stiff throttle has always been a nuisance, be interesting to see how it goes.

1980 Persian Aqua DHC

MikeRotherham · Postby **MikeRotherham** » 27 Dec 2014 14:05

Hello Steve,

Be interesting to see pictures of the linkage in place.

The throttle pedal on my car has always been stiff despite a new cable and lubricating it within an inch of its life.

Can't picture how it fits.

Regards

Mike.

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