Throttle sticking

PostPost by: blueseamonkey » Mon Nov 14, 2005 1:38 pm

This problem may or may not have some relation to the carb difficulties I am having (see other post) but I thought it would make more sense to have the answers separate, and it started before my carb problems too.
For the last few days my throttle has been sticking on for a few seconds after I release it. Its not too noticeable when staying in the same gear, although I'm perhaps using the brake a little more now, but the main time I notice it is changing up a gear, when the engine revs up until it gets back in gear. The pedal itself seems to move freely without getting stuck. I can't see any obvious problems with the cable at the carb end either, although unfortunately I hadn't looked closely enough at it before the problem started :oops:
At the moment I'm managing to keep it under control by releasing the pedal a few seconds earlier than I would normally for a gear change, but I have a further longish drive coming up later this week and it would be good to have it fixed by then.
Anyone have any clues?
Thanks
Rick
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PostPost by: type26owner » Mon Nov 14, 2005 2:09 pm

Replace the cable and sheath. They only last about 50k miles and then they wearout. You should lubricate it every 10k miles with a motorcycle cable lubricator. Every motorcycle shop sells them. Here's what one looks like. I always stock a spare cable. It should actuate so freely that you can barely feel any resistance when depressing the pedal if you want drive out to the edge of the traction circle. Yehaww! :lol:
http://www.motorcycle-accessories-warehouse.co.uk/assets/product_images/CLBBLK.jpg
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PostPost by: types26/36 » Mon Nov 14, 2005 3:24 pm

blueseamonkey wrote:This problem may or may not have some relation to the carb difficulties (see other post) and it started before my carb problems too.
For the last few days my throttle has been sticking on for a few seconds after I release it. Its not too noticeable when staying in the same gear,


I note you said it started before the AA man fiddled with the carbs but he may have made the "sticking" worse. If the balace screw between the carbs has been altered and not set correctly it can give impression of a sticking throttle (i.e. engine revs dont return to idle very quickly)
An other possibility is the return springs being defective, each carb has its own return spring but these are only accessible by removeing the carb as they are behind a plate. There is also an exterior spring which returns the throttle cable, this is attached on the bottom of the air box, it is possible it has become unhooked/broken ......this would be the first thing to check.
In my opinion it sounds like the carbs need setting (not necessarily to the degree Keith works too) and if you do not feel confidant doing it there should be someone in your area who could do a tune up, webers have been around a long time and fitted on other cars as well as Lotus.
Brian.
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PostPost by: twincamman » Mon Nov 14, 2005 3:32 pm

my ?lan had similar problem problem it was solved by lubricating the shaft that holds the pedals under the foot well at the extreme outer rotation points---- used a penetrating grease in a can on all points after that -----slick as Saturday nite hooker now :? ed [ also check the return spring is attached to the pedal ]
Last edited by twincamman on Tue Nov 15, 2005 8:48 pm, edited 1 time in total.
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PostPost by: type26owner » Mon Nov 14, 2005 6:28 pm

There is a high wear rate part of the throttle linkage you should inspect for damage. It's the interconnection linkage between the carburetors but the one fastened to the rear carbie. A divot is worn into the sheetmetal underneath the adjustment screw. If that is disturbed by having someone adjust it then it can hang open the throttle by sticking. I always keep a spare in my Weber parts box.

BTW, that area should be lubricated with heavy oil including under the spring loaded plunger.
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PostPost by: freddy22112211 » Wed Nov 16, 2005 6:09 pm

Probably not the answer for you - but my elan recently had exactly the same symptoms - engine running on a little, but throttle free.
It was a duff sparking plug!! - (getting too hot?) - this plug, although having the normal N7Y number was longer than the others!!!
(Later replaced the N7Ys with BP6ES, which are great by the way).
Gordon
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PostPost by: twincamman » Mon Nov 21, 2005 7:02 pm

ok ---- i have been looking at getting the carbs back to normal----but that may not have been the original problem----my money goes on a worn throttle cable binding on the interior covering ----I suggest change the cable [ a good idea on any old car] and see if it solves the problem :oops: ed-----do let us all know what the problem was
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PostPost by: blueseamonkey » Mon Nov 21, 2005 8:23 pm

Ok, well things have improved a little. I have greased the shaft in the pedal box, I have oiled the throttle linkage at the carbs and checked all other points. I'm going to track down a new cable in the next few days as the old one could probably do with replacing although I don't think its the primary cause of my current problem.
You see, having done these things, what's happening now is that the throttle is only causing problems when I push down on one of the other pedals. So if I press on the clutch, I get a rise in revs more than I used to, and if I push on clutch and brake together its even worse. Even pressing the brake on its own causes the throttle pedal to go down :shock:
Maybe I just need more grease, will try again this weekend if the car's not totally frozen!
Rick
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PostPost by: gjz30075 » Mon Nov 21, 2005 8:37 pm

Could be that your whole pedal shaft is moving up and down with pedal actuation and causing the throttle pedal to move. I've seen some pretty worn outboard shaft pivots.

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PostPost by: twincamman » Mon Nov 21, 2005 9:10 pm

ok ---- all the pedals are on a common shaft -----lube the sh*t out of the pedal shaft wirh loobit or some other penetrating light grease make sure the return spring on the throttle pedal is hooked up on both throttle and brake ---] the clutch doesnt have one ] -----add a slightly stronger return spring at the carb end and-things should get better 8) but im still betting on the cable ---ed
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PostPost by: type26owner » Tue Nov 22, 2005 4:10 am

Rick,
I leave about a 1/4" of slack in the throttle cable so the flexing of footbox does not affect the idling speed. The happy pedal when fully depressed should just open the butterflies fully. I remember having the throttle getting hung open slightly from the sheath rubbing on the inside of the bonnet but I have a LHD car. Look for some rubbing witness marks and apply some lube there. I made a restraining bar that is really smooth to keep the sheath from ever rubbing on a bonnet again. The real reason was everytime I closed the bonnet the idle speed would increase by about 200 rpms because the sheath tries to assume the shortest lenght possible when it's allowed but it gets flattened and elongated under the bonnet. That gets old and annoying.
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