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1983 Turbo diffuser Assembly shut off Valve issue

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I am a first time user and this is my first post. I have a 1983 Esprit Turbo Special Edition(North American Investors Edition). I had noticed over the past year the car lost the ability to rev over approx 4700 rpm after full running temp for a long period of time. When cold the car appears to have full power and can pull high rpm's. I took the intake diffuser off to check the shut off valve and noticed it is not opening fully. There is an operating cam that appears to be either warn down or the tip is broken off. The part number for this cam is A910E9024. I cannot find any info or locate this part anywhere. I have noticed that not all cars have this shut off valve. In my parts book there are two listings one without and one with the valve. Can someone tell me if this valve is required and if so where I could get the replacement part? Also could the partially opening valve be the issue of restricted rpm when hot? If not any other ideas?

 

Any assistance would be greatly appreciated.

 

Thanks.

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post-19151-0-38232400-1431888203.jpg

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Wow. No replies. I know I accidentally put this under the incorrect topic but I thought/hoped I would get some input with so much experience out there.  I modified the cam and adjusted the linkage to get full open. Car is now pulling 5800 RPM before it bogs. Still a little under what it should do. Any thoughts? anybody?

Once again, any input would be greatly appreciated.

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I'll have my twopennorth on this. I've never seen this part; must be specific to the American cars... A photo from a bit further away would be useful, as I can't even see exactly where it fits. There seems to be some capsule thingy which operates the valve. What operates that? Pressure? Temperature? Where does the pipe go....between the turbo and the plenum? The cam you refer to looks to me as if it is intended to be that shape... Certainly, if the pipe does go between the turbo and the plenum, then the valve not opening fully would definitrly restrict RPM.

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Seems like something well worth taking off and throwing away :)

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Welcome to TLF Paul. :welcome:

Can't say as I have seen that either on any car. I would look to scrap the system. Is it possible it was for emissions but has finally given up?

You should duck over to the Introductions section and say hi in there as well.

ps Just went to Canada (west coast) on a holiday. Beautiful place.

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I have attached the parts book images of the part and location. I do not see any valuable use for this part other than keeping the car 100% original. I may remove it and keep it for re-installation if required later.

The Cam is part number 036. it is a different shape than mine as there is a piece worn or broken off. It is also catching on the flat area so I filed it round as the part in the parts image #036 

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The valve complete is just below the part reference 027 and it has a reference to Sheet 2

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Just to add. When the car is cold the RPM will easily go over 7000 if you don't keep a close eye on it. When it is warm it was only getting to 4700 until I modified the part and adjusted the valve to open fully. As mentioned earlier it will now pull 5800rpm but then bogs and looses all power until I let off and shift to the next gear and it will pull hard again but will not go over 5800rpm. The engine has to be at full hot running temp for a while before the revs become limited. I can have a little fun for a while before it acts up.

 

For Micheal who has been to the west coast of Canada, I live in Edmonton in central Alberta just east of the Rocky Mountains. It is beautiful once you get past the long winter. I enjoy the Lotus from beginning of May to end of September then she is left on display in the corner of my heated garage. The car never sees below 10C.

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We actually went through the Rockies and went on the Rocky Mountaineer. Thoroughly enjoyed ourselves. We were there in summer though, which our guide told us was vastly different to winter.

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I know from frequenting the Ferrarichat forum that US car owners use language to describe parts which nobody else understands. There was so much extra gubbins on US cars of this era, most of which can be removed such as evaporative control systems, air injection, the strangely-named "smog pump" etc.

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Where does the capsule connect to? A pretty odd device. As has been suggested...take it off and throw it away. Plug the pipe to the capsule and the holes in the side of the tube....the standard British turbo has none of this gubbins and you'd be better of with it all in the bin! I wonder if there is any other "emissions control" rubbish that could be causing further problems?

 

I was in Edmonton back in 1978; Commonwealth Games year. My year for wandering around North America! Went back from Vancouver to Montreal on CN rail....they ran a scheduled service in those days, one train a day.

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