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Smithy111

throttle not returning to rest

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Today i started up and idle was around 2k blip the throttle and drops back to where it should be. Found the throttle butterfly on the carbs not quite returning fully to idle position. Cable seems to have a bit of slack so could it just be the spring on the carbs or slightly sticking cable? Drop of oil down the cable?

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Is the retaining fixing down by the peddle secure?


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Don't use oil on the cable. It will attract dirt and become sticky. Use a dry graphite lubricant.

 

That said, have a look at the throttle cable on the pedal side, where it comes out of the sheath.

 

Your symptom is what you get when one cable strand comes unraveled.


Atwell Haines

'88 Esprit

Succasunna, NJ USA

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1 hour ago, Chillidoggy said:

Definitely a warranty job, that.

Hope the boot doesn’t leak - or the seat squeak 


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I’ll check that but there seems to be enough slack at the carbs for it to return not like the cable is stopping it?

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When my throttle cable frayed, it was sticking really intermittently. Worth a peek, up under the dash. :no


Atwell Haines

'88 Esprit

Succasunna, NJ USA

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Ok so I’ve checked the cable and all looks and feels good at both ends the cable clamp at the carb end seems to jump about a bit in the throttle lever. How the hell do you adjust the cable!?

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Did you release the pedal end so that you could pull the cable out a couple inches, for inspection? :blush:

 

Adjust idle with the slotted screw on the quadrant.   Once you set that, adjust the cable for a SLIGHT amount of slack when the engine is fully warm. (If you adjust it cold, it will be too tight when warm!)

The twin nuts on the cable sheath (near the intake cam cover) is where the sheath adjustment is.

 

From memory, my car had ~15 threads showing on the air box side as a base adjustment.


Atwell Haines

'88 Esprit

Succasunna, NJ USA

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17 hours ago, Smithy111 said:

Ok so I’ve checked the cable and all looks and feels good at both ends the cable clamp at the carb end seems to jump about a bit in the throttle lever. How the hell do you adjust the cable!?

Where it couples to the engine on the bracket should be a threaded part like on bike brakes.

or - you can pull the carpet back by the pedal - and adjust there by loosening the clamp screw on the sheathing and moving the sheath portion in or out if that makes sense


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Thanks guys, ill try that as its very difficult to drive but Its going into a specialist for a full look over next weekend as there's a few things that need attention so might be safest to not use it till then.

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On 28/05/2018 at 13:30, CarBuff said:

Don't use oil on the cable. It will attract dirt and become sticky. Use a dry graphite lubricant.

This. I accidentally used gearbox oil on mine back in the day and had it stick like crazy a month later. Sewing machine oil was better though. 


Vanya Stanisavljevic '91 Esprit SE | '91 Elan SE | '97 XK8

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7 hours ago, Smithy111 said:

Thanks guys, ill try that as its very difficult to drive but Its going into a specialist for a full look over next weekend as there's a few things that need attention so might be safest to not use it till then.

You don’t need a specialist if you can use a spanner 👍


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If it was mine, I'd disconnect the cable at the carb end (solderless niple) to isolate the carbs from the cable.   This will allow you check its not the carb linkage is not sticking or being fouled independently from the cable.   Do you have 2 return spings on the carbs - 1 long central one and a U shaped one that acts on the lever? 

Once disconnected you will also be able to check the smoothness of the cable easier.

A stuck open throttle can destroy an engine.....   (Can also be pretty scary)

 

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It’s got what looks like a little the inside bit from a terminal block on the cable at the carb end which I think it wrong as Webber’s I’ve mucked about with have a cylinder shaped cable terminator that swivels as the throttle is opened and closed keeping the cable strait. Is this correct for dellortos?

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Broadly speaking sounds correct.  A photo could confirm.   The end of the inner cable is fixed and the linkage lever acts upon the outer cable!  

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ISTR now, that on USA DellOrto setups there is a plate bolted under the intake manifold/plenum that retains a second throttle return spring. (The plate also mounts other USA emissions pieces.)  This spring is often misplaced or hooked onto the wrong place, which lessens throttle return action.

 

Worth a look.


Atwell Haines

'88 Esprit

Succasunna, NJ USA

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Also worth checking that none of those hose clamps are interfering with the linkage. 

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Maybe move it slightly? I don’t need full throttle as I’m running in the freshly rebuilt engine still

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Ok so ive temporarily fixed this to make it driveable again and theres no problem with the carb end linkage/return spring its got the wrong throttle cable fitted. Looks like at some point the inner cable has been replaced on its own and terminated with a screw down clamp which I have loosened and moved back a few mm to allow some slack. How easy is it to thread a complete new correct part cable and sheath whole?

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